fix TxRedisManager reconnect with failing unittest
Reduce Redis reconnection time and add reconnection test.
Base reconnect wait time in tests on factory reconnect delay.
Use a decorator for skipping tests if fake redis is being used.
Merge pull request #884 from praekelt/feature/issue-610-session-manager-supporting-reconnected-txredis-client

Fix TxRedisManager sub-manager reconnecting.