Bump version after release

Signed-off-by: Jordan Borean <jborean93@gmail.com>

Author: jborean93

setup.py

@@ -310,7 +310,7 @@ def gssapi_modules(lst):
 
 setup(
     name='gssapi',
-    version='1.12.0',
+    version='1.12.1.dev0',
     author='The Python GSSAPI Team',
     author_email='jborean93@gmail.com',
     packages=['gssapi', 'gssapi.raw', 'gssapi.raw._enum_extensions',