pytest-factoryboy does not support pytest3.0+

Author: leo-naeka

setup.py

@@ -105,7 +105,8 @@ def get_package_data(package):
     tests_require=[
         'pytest-factoryboy',
         'pytest-django',
-        'pytest>=2.8',
+        'pytest>=2.8,<3',
+        'django-polymorphic',
     ] + mock,
     zip_safe=False,
 )