Test Activities with mocked Context

[sam-goodwin]

Do we need to add any capabilities into TestEnvironment to help with unit testing individual activities. For example, if i want to call an activity from within a test - it will need the globals properly set for things such as token or else asyncResult won't work.

• [ ] heartbeat
• [x] asyncResult

[thantos]

asyncResult works end to end. Heartbeat impl is not complete.