Move versions to post-release

Author: Guido van Rossum

extensions/setup.py

@@ -4,7 +4,7 @@
 
 from distutils.core import setup
 
-version = '0.2.0'
+version = '0.3.0-dev'
 description = 'Experimental type system extensions for programs checked with the mypy typechecker.'
 long_description = '''
 Mypy Extensions

mypy/version.py

@@ -1,7 +1,7 @@
 import os
 from mypy import git
 
-__version__ = '0.511'
+__version__ = '0.520-dev'
 base_version = __version__
 
 mypy_dir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))