Fix for options hash so that expiry is applied

This isn't the prettiest method and it probably should be taken care of upstream but all the tests pass locally and it fixes the problem.

First, I changed the test to check for session expiry so that it's not applied in the dummy test controller but in the options set within the initializer.  This exposed that the ttl was not being set.  This is because when rack/session/redis sets a session it passes in it's own options which are overriding the options hash that the TTL module should be seeing.  Resetting the hash (if it's a hash) to the redis-server options fixes this.

This may also solve problems such as https://github.com/jodosha/redis-store/pull/166 and should close https://github.com/jodosha/redis-store/issues/171