Remove Flask install step

Home.md

@@ -6,7 +6,6 @@ Production bots should continue to be developed using the [v3 SDK](https://githu
 
 The v4 SDK consists of a series of [libraries](https://github.com/Microsoft/botbuilder-python/tree/master/libraries). To build them locally, see [Building the SDK](building-the-SDK).
 
-- Install [Flask](http://flask.pocoo.org/)
 - Install [Bot Framework Emulator](https://github.com/Microsoft/BotFramework-Emulator)