Update install_requires

Author: JamalZeynalov

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name="swagger-coverage",
-    version="2.2.0",
+    version="2.2.1",
     author="Jamal Zeinalov",
     author_email="jamal.zeynalov@gmail.com",
     description='Python adapter for "swagger-coverage" tool',