L1: Refactor testing and state management (#76)

SQLiteL1: Initial Implementation (#62)

Merging david's work to master

The TRAVIS_PULL_REQUEST environment variable is actually 'false' for …

…builds that are not pull requests.

Integrated: Dynamically accept a TTL or expiration (#40)

APCuL1: We cannot safely set the high water mark at deletion (#38)

UnserializationException: Throw when failed on get(). (#33)

Safely handle unserialize on get (#32)

LICENSE: Update to Pantheon (#30)

PHPUnit: Remove HTML coverage comment (#21)

Add garbage collection for expired L2 items. (#18)