Fix timeout in test_slave_user_removed int-test

The test_slave_user_removed int-test polls to check that the
slave user account is removed, but doesn't currently have a time
out set. This means that a failure in this test causes the entire
suite to spin, and ultimately time out. Fix this by adding a 3 min
timeout to this test.

Change-Id: I5f869c7d3cb0587409b5a12a89ed673e57552b82
Closes-bug: 1399583

trove/tests/api/replication.py

@@ -216,6 +216,7 @@ class DetachReplica(object):
         assert_equal(stdout, "0\n")
 
     @test(depends_on=[test_detach_replica])
+    @time_out(3 * 60)
     def test_slave_user_removed(self):
         if CONFIG.fake_mode:
             raise SkipTest("Test not_read_only not supported in fake mode")