Cleanup a bit and use hubot-botframework for MS Teams support

[blag]

• Adds unit tests for adapters
• Pins hubot-help version to 0.2.2
• Adds adapter for MS Teams
• Rename createExecution function to sendAliasExecutionRequest so it's a bit clearer how the function is different than executeCommand
• Send source_context in sendAliasExecutionRequest function
• Adds tests for BotFramework adapter
• Cleans up some (but not all) layering violations with the HipChat adapter
• Adds tests for normalizeAddressee functions on adapters
• Adds comments to adapter functions
• st2 changes in Add chat context to chatops st2#4609
• st2chatops in Cleanup a bit and use hubot-botframework for MS Teams support st2chatops#121
• Documentation for configuring Microsoft Teams with BotFramework in Add configuration steps for Microsoft Teams to ChatOps st2docs#872

[Kami]

LGTM, looking forward to integration / end to end tests in the future 👍

[arm4b]

@blag Worth also updating CHANGELOG record with this new addition:
https://github.com/StackStorm/hubot-stackstorm/blob/master/CHANGELOG.rst