Add return type to RowProxy:items() method (#120)

Author: fxleblanc

sqlalchemy-stubs/engine/result.pyi

@@ -1,4 +1,4 @@
-from typing import Any, List, Mapping, Optional, Iterator, Union
+from typing import Any, List, Mapping, Optional, Iterator, Union, AbstractSet, Tuple
 from ..sql.schema import Column
 
 def rowproxy_reconstructor(cls, state): ...
@@ -22,7 +22,7 @@ class RowProxy(BaseRowProxy):
     def __eq__(self, other): ...
     def __ne__(self, other): ...
     def has_key(self, key): ...
-    def items(self): ...
+    def items(self) -> AbstractSet[Tuple[str, Any]]: ...
     def keys(self): ...
     def iterkeys(self): ...
     def itervalues(self): ...