Feature/unit tests

[syedhassaanahmed]

• Consolidated Microsoft.Bot.Builder to use the same version 3.8.3.0 in all projects in order to avoid strange build errors.
• Renamed benchmark class to BotFrameworkApplicationInsightsInstrumentationBenchmarks for clarity.
• Wrapped HttpClient used by SentimentManager into IHttpCommunication
• Added Unit tests for both Manager classes.
• Updated Readme to use DependencyResolver