Notification observers removed for parallel testing

Author: MartinCardozo-SDK

SplitTests/Streaming/SyncManagerTest.swift

@@ -263,6 +263,9 @@ class SyncManagerTest: XCTestCase {
             default:
                 print("nones")
             }
+            
+            nHelper.removeAllObservers()
+            syncManager.stop()
         }
     }