Use Lettuce Redis client; Redis module fixes

[artembilan]

The Lettuce client is based on the Netty and more stable, than Jedis
therefore we get a performance improvement for tests
(it saves us at about 30 seconds).
Also this client doesn't fail for me on Windows sporadically (very often)
with the ConnectionClosedException

• After switching to the Netty-based client, we expose the interrupted
  Thread issue in the LockRegistryLeaderInitiator.
  If we interrupted (expected behavior), we try to unlock calling
  RedisLockRegistry, but Netty client reject our request because the
  thread is interrupted, therefore we never delete the lock when we yield
  our leadership.
  Fix the issue with shifting a RedisTemplate.delete() operation to the
  ExecutorService when the current thread is interrupted
• Allow to configure such an ExecutorService and timeout to wait for
  the submit() result
• Refactor RedisAvailableRule and all the Redis tests do not expose
  the target RedisConnectionFactory implementation.
• Make all the test-cases based on the connectionFactory created by
  the RedisAvailableTests.setupConnectionFactory()
• Tweak some unnecessary timeouts and sleeps for better tests task
  throughput

[artembilan]

We may consider this for back-porting, especially the fix for RedisLockRegistry.

[garyrussell]

org.springframework.integration.redis.leader.RedisLockRegistryLeaderInitiatorTests > testDistributedLeaderElection FAILED
java.lang.AssertionError at RedisLockRegistryLeaderInitiatorTests.java:144
142 tests completed, 1 failed, 3 skipped

[artembilan]

The Travis is green after the second attempts, but there is indeed something else to do there.
Let's see how it works for you and on CI server!
The Log4j2LevelAdjuster should help us.

[artembilan]

@garyrussell ,

Do you want a separate PR for back-porting or are you OK to cherry-pick this fully ?

[garyrussell]

Before backporting, I think we need to be sure the src/main changes still work with the Jedis library.

If you've already done that, we can cherry-pick; if not, we should backport just the src/main changes first.

[garyrussell]

I just reverted src/test and build.gradle and the build is green.

Attempting cherry-pick...