MXS-1566 Rejoin old slave

This test tests the following:

- Regular master-slave setup
- Create a table, insert some data
- Sync all slaves
- Stop a slave
- Insert some more data
- Sync remaining slaves
- Stop the master
- Expect the failover mechanism to pick a new master
- Bring up the slave
- Expect the slave to be rejoined

maxscale-system-test/.gitignore

@@ -109,6 +109,7 @@ mysqlmon_failover_manual
 mysqlmon_failover_manual2_4
 mysqlmon_failover_manual2_3
 mysqlmon_failover_manual2_2
+mysqlmon_failover_rejoin_old_slave
 mysqlmon_failover_rolling_master
 mxs1045
 mxs1071_maxrows