Try normalized alpha version number

Photonios · Photonios · commit abc6004eaead · 2018-01-25T00:10:49.000+02:00
diff --git a/setup.py b/setup.py
@@ -7,7 +7,7 @@
 
 setup(
     name='django-postgres-extra',
-    version='1.21.a1',
+    version='1.21a2',
     packages=find_packages(),
     include_package_data=True,
     license='MIT License',
