Modified Configuration implementation to accept void Actions
- Fixed spec name in ExpectationExpressionSpec.
- Added and implemented specs for setting expectations on void actions.
- Added constructor to ExpectationExpression taking Expression<Action<TController>>.
- Added overload to For<TController> in PolicyExpectations taking Expression<Action<TController>>.
- Added overload to Expect<TController> in PolicyExpectationsExpression taking Expression<Action<TController>>.
- Added VoidAction to SampleController to enable testing of void actions.
- Reformatted extensions and cleaned up xml comments.
Merge branch 'feature-void-actions' into develop

Closes #67
Closes #57