Initial Redis support wit Predis client library
Mention support for Redis
fixes infinite loop in mutex dtor
Added test case to prove this bug
Add redis-server to travis services
Merge pull request #3 from arvenil/update-travis

Add redis-server to travis services
Infinite loop in mutex dtor when backend is unavailable - unit test
Infinite loop in mutex dtor when backend is unavailable - fix
test/predis mock: makes available property non-static