[REEF-726] Fix a race condition with completed Containers

This removes the releasing of Evaluators directly in `YarnContainerManager` and
instead delegates the job to `EvaluatorManager` on container complete.

JIRA:
  [REEF-726](https://issues.apache.org/jira/browse/REEF-726)

Pull Request:
  This closes apache#476

lang/java/reef-common/src/main/java/org/apache/reef/runtime/common/driver/evaluator/EvaluatorManager.java

@@ -556,7 +556,6 @@ public void onResourceStatusMessage(final ResourceStatusEvent resourceStatusEven
               .append(this.task.get().getId())
               .append("] was running when the Evaluator crashed.");
         }
-        this.isResourceReleased = true;
 
         if (resourceStatusEvent.getState() == ReefServiceProtos.State.KILLED) {
           this.onEvaluatorException(new EvaluatorKilledByResourceManagerException(this.evaluatorId,

lang/java/reef-runtime-yarn/src/main/java/org/apache/reef/runtime/yarn/driver/YarnContainerManager.java

@@ -343,8 +343,6 @@ private void onContainerStatus(final ContainerStatus value) {
           status.setState(ReefServiceProtos.State.FAILED);
         }
         status.setExitCode(value.getExitStatus());
-          // remove the completed container (can be either done/killed/failed) from book keeping
-        this.containers.removeAndGet(containerId);
         break;
       default:
         LOG.info("Container running");
@@ -356,6 +354,7 @@ private void onContainerStatus(final ContainerStatus value) {
         status.setDiagnostics(value.getDiagnostics());
       }
 
+      // The ResourceStatusHandler should close and release the Evaluator for us if the state is a terminal state.
       this.reefEventHandlers.onResourceStatus(status.build());
     }
   }