Added a new CrossZoneLoadBalancing conformity rule and a test
Merge branch 'master' into add_cross_zone_lb_conformity_rule

* master:
  The original condition should be returned in addition to the new one since unit-test will otherwise fail: the reason for that is that the unit-test checks two things: 1. selected instances 2. terminated
  maxTerminationsPerDay was checked only once for the group before the iteration over the instances while ee should check if maxTerminationsPerDay was exceeded before trying to terminate *any* instance.
Merge pull request #138 from radonsky/add_cross_zone_lb_conformity_rule

Add cross-zone load balancing conformity rule