VOL-1385 VOL-2524 OMCI Test Task needs to be able to stop

Add method to stop the twisted LoopingCall

Release 2.3.12

Change-Id: I74951073e815f3f9fcb60d395daa08b3841e5399
diff --git a/VERSION b/VERSION
index f470771..b001d23 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.11
+2.3.12
diff --git a/pyvoltha/adapters/extensions/omci/tasks/omci_test_request.py b/pyvoltha/adapters/extensions/omci/tasks/omci_test_request.py
index a7020ee..f64fda0 100644
--- a/pyvoltha/adapters/extensions/omci/tasks/omci_test_request.py
+++ b/pyvoltha/adapters/extensions/omci/tasks/omci_test_request.py
@@ -144,6 +144,11 @@
         if self.default_freq > 0:
             self.lc.start(interval=self.default_freq / 10)
 
+    def stop_collector(self):
+        """ Stop the collection loop"""
+        if self.lc is not None and self.default_freq > 0:
+            self.lc.stop()
+
     def format_id(self, event):
         return 'voltha.{}.{}.{}'.format(self.core_proxy.listening_topic,
                                         self.device_id, event)