Prepping for v0.3.0 release

aka dropping the hammer of modernization!
Adding some encoding comments to appease rubocop on 1.9.3
Spec example for set_session returning a session id
Fetching session spec, using fake redis for specs
Spec example for destroying a session
Spec example for fetching when redis is down
Merge pull request #9 from modcloth/v0.3.0-release-prep

Prepping for v0.3.0 release