fix unit test

Author: William Hou

SingularityService/src/test/java/com/hubspot/singularity/scheduler/SingularitySchedulerTest.java

@@ -2338,7 +2338,7 @@ public void testBounceReleasesLockWithAlternateCleanupType() {
   @Test
   public void testIncrementalBounce() {
     initRequest();
-    resourceOffers(2); // set up agents so scale validate will pass
+    resourceOffers(3); // set up agents so scale validate will pass
 
     SingularityRequest request = requestResource
       .getRequest(requestId, singularityUser)