Bump version to 13 (#187)

Author: software-dov

packages/gapic-generator/setup.py

@@ -25,7 +25,7 @@
 
 setup(
     name='gapic-generator',
-    version='0.12.0',
+    version='0.13.0',
     license='Apache 2.0',
     author='Luke Sneeringer',
     author_email='[email protected]',