Setup unit tests.

Makefile

@@ -3,3 +3,6 @@ build:
 
 test:
 	cd integration_tests && docker-compose down && docker-compose run --rm tests
+
+unittest:
+	pytest tests/

tests/test_extend.py

@@ -0,0 +1,14 @@
+from graphene import Int, String
+
+from graphene_federation.extend import external, requires
+
+
+def test_external():
+    field = external(Int(required=True))
+    assert field._external is True
+
+
+def test_requires():
+    fields = 'primaryEmail'
+    field = requires(String(), fields=fields)
+    assert field._requires == fields