Cannot build with iOS client SDK 3.0.1

[alexpyoung]

Describe the bug
Attempting to build the hello-react-native app with iOS SDK 3.0.1 fails even though the React Native SDK Podspec allows it

To reproduce

1. git clone https://github.com/launchdarkly/react-native-client-sdk.git
2. pushd react-native-client-sdk && npm link && popd
3. git clone https://github.com/launchdarkly/hello-react-native.git
4. pushd hello-react-native && npm link launchdarkly-react-native-client-sdk
5. npm install
6. pushd ios && sed -i '' 's/3.0.0-beta.3/3.0.1/g' Podfile
7. pod install
8. Link glog and DoubleConversion frameworks to React Pod target
9. react-native link
10. react-native run-ios

Expected behavior
Building the hello-react-native app with iOS SDK 3.0.x should succeed

Logs

▸ Building Pods/LaunchdarklyReactNativeClient [Debug]
▸ Check Dependencies
▸ Compiling LaunchdarklyReactNativeClient.swift

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:7:39: use of undeclared type 'LDObserverOwner'
    private var listenerKeys: [String:LDObserverOwner] = [:]
                                      ^~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:47:78: cannot assign value of type 'URL' to type 'String?'
            ldConfig.baseUrl = URL.init(string: config["baseUri"] as! String)!
                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:59:13: value of type 'LDConfig' has no member 'eventCapacity'
            ldConfig.eventCapacity = config["eventsCapacity"] as! Int
            ^~~~~~~~ ~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:63:13: value of type 'LDConfig' has no member 'eventFlushInterval'
            ldConfig.eventFlushInterval = TimeInterval(config["eventsFlushIntervalMillis"] as! Float / 1000)
            ^~~~~~~~ ~~~~~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:67:42: cannot assign value of type 'TimeInterval' (aka 'Double') to type 'NSNumber?'
            ldConfig.connectionTimeout = TimeInterval(config["connectionTimeoutMillis"] as! Float / 1000)
                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:71:13: value of type 'LDConfig' has no member 'flagPollingInterval'; did you mean 'pollingInterval'?

            ldConfig.flagPollingInterval = TimeInterval(config["pollingIntervalMillis"] as! Float / 1000)
            ^~~~~~~~ ~~~~~~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:75:13: value of type 'LDConfig' has no member 'backgroundFlagPollingInterval'
            ldConfig.backgroundFlagPollingInterval = TimeInterval(config["backgroundPollingIntervalMillis"] as! Float / 1000)
                        ^

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:83:66: use of unresolved identifier 'LDStreamingMode'
            ldConfig.streamingMode = (config["stream"] != nil) ? LDStreamingMode.streaming : LDStreamingMode.polling
            ^~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:87:13: value of type 'LDConfig' has no member 'enableBackgroundUpdates'
            ldConfig.enableBackgroundUpdates = !(config["disableBackgroundUpdating"] as! Bool)
                                                                                             ^~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:91:13: value of type 'LDConfig' has no member 'startOnline'
            ldConfig.startOnline = !(config["offline"] as! Bool)
            ^~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:95:13: value of type 'LDConfig' has no member 'isDebugMode'
            ldConfig.isDebugMode = config["debugMode"] as! Bool
            ^~~~~~~~ ~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:102:20: use of unresolved identifier 'LDUser'
        var user = LDUser()
            ^~~~~~~~ ~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:168:40: type 'LDClient' has no member 'shared'
        let stringFlagValue: String? = LDClient.shared.variation(forKey: flagKey)
                                      ^~~~~~~~ ~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:283:42: use of undeclared type 'LDObserverOwner'
        let flagChangeOwner = flagKey as LDObserverOwner
                                         ^~~~~~~~~~~~~~~

❌  /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift:293:17: type 'LDClient' has no member 'shared'
        resolve(LDClient.shared.config.enableBackgroundUpdates)
                                         ^~~~~~~~~~~~~~~

** BUILD FAILED **
The following build commands failed:
	CompileSwift normal x86_64 /Users/alex.young/q/hello-react-native/node_modules/launchdarkly-react-native-client-sdk/ios/LaunchdarklyReactNativeClient.swift
	CompileSwiftSources normal x86_64 com.apple.xcode.tools.swift.compiler
(2 failures)

SDK version
1.0.1

Language version, developer tools
OS/platform

React Native Environment Info:
  System:
    OS: macOS High Sierra 10.13.6
    CPU: (8) x64 Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz
    Memory: 182.06 MB / 16.00 GB
    Shell: 5.3 - /bin/zsh
  Binaries:
    Node: 8.15.1 - ~/.nvm/versions/node/v8.15.1/bin/node
    Yarn: 1.15.2 - /usr/local/bin/yarn
    npm: 6.4.1 - ~/.nvm/versions/node/v8.15.1/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  SDKs:
    iOS SDK:
      Platforms: iOS 12.1, macOS 10.14, tvOS 12.1, watchOS 5.1
  IDEs:
    Android Studio: 3.4 AI-183.5429.30.34.5452501
    Xcode: 10.1/10B61 - /usr/bin/xcodebuild
  npmPackages:
    react: 16.6.3 => 16.6.3
    react-native: 0.57.7 => 0.57.7
  npmGlobalPackages:
    launchdarkly-react-native-client-sdk: 1.0.1
    react-native-cli: 2.0.1

Additional context
I noticed similar logs being discussed in #1. I also see the same behavior when using iOS SDK 3.0.0. I can successfully build 3.0.0-beta.3. One would expect forwards compatibility with newer libraries. One odd thing I noticed is that 3.0.0-beta.3 seems to be completely divergent from master, where the expectation of semantic versioning is that 3.0.0.beta.3 is behind 3.0.0 and 3.0.1

[torchhound]

Hi @alexpyoung iOS SDK version 3.0.1 is completely incompatible with any version of our React Native SDK. Only 3.0.0-beta.x and 4.x.x versions are or will be compatible with React Native. iOS 3.0.1 is written in Objective C while 3.0.0-beta.x and 4.x.x are written in Swift. Versions 2.x.x were bumped to 3.x.x and 3.0.0-beta.x were bumped to 4.x.x to provide support for Xcode 10.2.