Trivial fix typos

Change-Id: I4c7d3a0d815a616d1ba2c0d26135db5f2aea0c2f

watcher/api/controllers/v1/types.py

@@ -181,7 +181,7 @@ class JsonPatchType(wtypes.Base):
 
     @staticmethod
     def mandatory_attrs():
-        """Retruns a list of mandatory attributes.
+        """Returns a list of mandatory attributes.
 
         Mandatory attributes can't be removed from the document. This
         method should be overwritten by derived class.

watcher/api/controllers/v1/utils.py

@@ -55,7 +55,7 @@ def validate_sort_dir(sort_dir):
 
 
 def validate_search_filters(filters, allowed_fields):
-    # Very leightweight validation for now
+    # Very lightweight validation for now
     # todo: improve this (e.g. https://www.parse.com/docs/rest/guide/#queries)
     for filter_name in filters.keys():
         if filter_name not in allowed_fields: