Update Kubernetes dependencies to 1.14.1 and adjust code

[timoreimann]

Besides being more up-to-date in general and supporting Kubernetes 1.14, the update will also allow us to customize LB names in the future (and thus address #102).

Changes in detail:

• Update package imports.
• Implement new interface function around load balancer naming (without modifying the naming schema).
• Use cobra command-based bootstrapping method to ensure all flags are set properly. (This will require enabling the allow-untagged-cloud flag on the CLI.)
• Update end-to-end tests.
• Follow upstream in switching from glog to klog.

Note: Due to the way cloud providers are to be initialized now (basically by calling a factory function that returns a Cobra command), we cannot in-code-enable the flag allowing untagged clouds easily anymore. As such, the flag should move to the CLI in form of the --allow-untagged-cloud parameter.

[timoreimann]

This supersedes #165.

[timoreimann]

I needed to pin the dependency for apimachinery (replace in Go modules lingo) to 1.14.1 for some reason. Haven't digged into why it's needed, but it certainly is.

[timoreimann]

Submitted an upstream fix for the workaround we had to do around the GCE-only flag problem (see main.go in this PR).

[jcodybaker]

One note about the docs, but otherwise good by me if it's well tested across our known versions.

[jcodybaker]

@timoreimann and I had an offline discussion about this. Because of the upstream changes were no longer able to do this, but it sounds like we need to change the parameters required to invoke the CCM. We should also update the documentation in this PR so they ride together.

[timoreimann]

Good catch -- I pushed a commit that updates the docs. PTAL again.

[timoreimann]

Also confirming that the new version was tested on Kubernetes 1.11 through 1.13. The latest release 1.14 will be tested as soon as images are readily available for us.