Unasync Chef

* Removed all async apis
* Refactored strategies to avois using the async apis
* Removed references to awaitCompletion and use Guava helpers
* Added a method in ChefContext to access the underlying api (ChefApi,
  HostedChefApi or PrivateChefApi)
Fixed typo
Use Futures.getUnchecked to get strategy results
Merge pull request #81 from nacx/unasync

Unasync Chef