Watson Developer Cloud Unity SDK v1.0.0

This is the first major release since the original Watson Developer Cloud Unity SDK. In this release, we remove the higher level Widget architecture to be added later as a separate package. All 3rd party plugins have been updated to their latest versions for compatibility across platforms. Dependency on credentials through a config.json file has been removed in favor of allowing users to choose how they want to consume credentials. Authentication through tokens has also been added. See the changelog for details.