Redis Testcontainer should be stopped after LettuceConnectionFactory

[vpavic]

Our Redis based integration tests are currently stopping Redis Testcontainer before LettuceConnectionFactory which causes shutdown waits due to Lettuce trying to complete pending commands. More details about this can be found in redis/lettuce#667.

Since we have several integration tests that spin up Redis Testcontainer, this adds up quite a lot of time to our build.

We should move management of Redis Testcontainer to application context by registering it as @Bean, similarly like we do in Gretty based integration tests, and having LettuceConnectionFactory depend on test container bean to ensure a clean shutdown.

[vpavic]

This reduced build time from 17 minutes down to less than 8 minutes on my machine.

Update: Jenkins is down to 11 minutes (previously 19) while Travis CI is down to 17 minutes (previously 26).