Changes fabfile runserver to point to runserver.py sted run.py

After setting up an initial project with ```fab newproject```, running fab runserver resulted in an error. The runserver command in the fabfile pointed to ```fab.local('python run.py' % fab.env)``` sted of ```fab.local('python runserver.py' % fab.env)```

Error message below...

        Welcome to Test Project. Great work! What's next?

        - Edit test_project/config.py to set up template values and adjust project settings.
        - Edit test_project/secrets.py to configure Google spreadsheet authentication variables.
        - Edit test_project/templates/index.html to edit your default template.
        - Edit test_project/static/js/app.js to edit your default Javascript app.
        - Run `fab runserver` and view your project at http://localhost:5000/test_project/

        Run `fab deploy` and `fab project:projectname deploy` to deploy to S3 if you have a bucket configured.

        Done.
        (tarbell)20:47 [tarbell-template]  ( master ✔✖)
        ... fab runserver
        Point your browser to http://localhost:5000/
        Type ctrl-c to quit.
        [localhost] local: python run.py
        python: can't open file 'run.py': [Errno 2] No such file or directory

        Fatal error: local() encountered an error (return code 2) while executing 'python run.py'

        Aborting.