add type definitions

[amarzavery]

This is what the adal-node module looks like in javascript. This PR ensures that it has all the type definitions in sync with js definition exported on require("adal-node").

> var adal = require("adal-node")
undefined
> adal
{ Logging:
   { LOGGING_LEVEL: { ERROR: 0, WARN: 1, INFO: 2, VERBOSE: 3 },
     setLoggingOptions: [Function: setLoggingOptions],
     getLoggingOptions: [Function: getLoggingOptions],
     LogOptions: { log: [Function: log], level: 0 } },
  AuthenticationContext: [Function: AuthenticationContext],
  setGlobalADALOptions: [Function: setGlobalADALOptions],
  getGlobalADALOptions: [Function: getGlobalADALOptions],
  MemoryCache: [Function: MemoryCache],
  AuthenticationParameters: [Function: AuthenticationParameters],
  createAuthenticationParametersFromHeader: [Function],
  createAuthenticationParametersFromResponse: [Function],
  createAuthenticationParametersFromUrl: [Function],
  createAuthenticationContext: [Function] }

Thanks to @mmaitre314. I have taken the initial version from the link he specified in #142 and modified it further.

[amarzavery]

closing in favor of #176