Use "sentinel failover" to force failover

* Use "sentinel failover" to force failover
** faster than kill redis instances
* set failover timeout to 1 min
** It makes sense with failover within localhost
* reduce instances : 1 Redis Server and 1 Sentinel
** port is not changed -> I'll changed later at end of refactoring
Let JedisSentinelPoolTest recognizes "aborted failover" and fail fast

* let unit test fail if -failover-abort-* message is produced while waiting to failover
** waiting more is meaningless, and there is nothing we can do
** we can request "sentinel failover" to failover again, but it may can fail again
Clean up JedisSentinelTestUtil

* remove all unused methods
* move JedisSentinelPoolTest.waitForJedisSentinelPoolRecognizeNewMaster to JedisSentinelTestUtil
** both JedisSentinelTest and JedisSentinelPoolTest can use this implementation
* introduce FailoverAbortedException
** throws when we subscribe sentinel channels and got message by "-failover-abort-*" channel
* respect Source Format to Java Convention (by Eclipse -> Source -> Format)
Revert "Clean up JedisSentinelTestUtil"

This reverts commit a3862bc2dd96805b85d2a99ed03e5d76c615e1d9.
Clean up JedisSentinelTestUtil

* remove all unused methods
* move JedisSentinelPoolTest.waitForJedisSentinelPoolRecognizeNewMaster to JedisSentin
** both JedisSentinelTest and JedisSentinelPoolTest can use this implementation
* introduce FailoverAbortedException
** throws when we subscribe sentinel channels and got message by "-failover-abort-*" c
* respect Source Format to Java Convention (by Eclipse -> Source -> Format)
Modify method sequence : public -> private
set sentinel failover-timeout longer (120000 ms)

* failover-timeout 60000 (ms) always success with local machine
** but sometimes failed with Travis CI
Shift Redis/Sentinel instances to remove unused index

* Redis instances : 6, 7, 8 -> 5, 6, 7
* Sentinel instances : 4 -> 3
Fix #550 : Removed redundant call to connectionPool.getResource() in method getConnectionFromSlot(int slot) in class JedisSlotBasedConnectionHandler
Merge pull request #551 from mayankdang/master

Fix #550 : Removed redundant call to connectionPool.getResource()
Merge pull request #546 from HeartSaVioR/sentinel_unit_test_revised

Sentinel unit test revised (use "sentinel failover", take care of "-failover-abort", etc)