Deprecate async apis. Fixes #70

* Deprecated all async apis.
* Refactored tests to extend BaseApiLiveTest.
* ChefContext now extends View.
* HostedChefApi now extends ChefApi.
* PatchedChefApi has been removed.
* Removed HostedChefContext and PrivateChefContext because they are now
  redundant. The concrete apis can be unwrapped from teh ChefContext
  view.
Merge pull request #77 from nacx/deprecate-async

Deprecate async apis. Fixes #70