Also implement __hash__ for tagged union members

.travis.yml

@@ -13,7 +13,7 @@ install:
 - pip install -r requirements-dev.txt
 - pip install .
 script:
-- pylint tagged_union
+- pylint tagged_union --py3k
 - pytest --cov=tagged_union
 after_success:
 - coveralls

tagged_union/__init__.py

@@ -87,6 +87,9 @@ def __repr__(self):
         def __eq__(self, other):
             return (self.name, self.args) == (other.name, other.args)
 
+        def __hash__(self):
+            return hash((self.name, self.args))
+
     class TaggedUnionMemberFactory:
         """Helper class for creating tagged union members.