manager: add trait checking to scheduler

circle/manager/scheduler.py

@@ -3,6 +3,8 @@ def get_node(instance, nodes):
     '''
     # Return first Node or None
     try:
+        req_traits = set(instance.req_traits.all())
+        nodes = [n for n in nodes if req_traits.issubset(n.traits.all())]
         return nodes[0]
     except:
         return None