add version option

Author: tony

vcspull/cli.py

@@ -68,15 +68,13 @@ def get_command(self, ctx, cmd_name):
 @click.option('--log_level', default='INFO',
               help='Log level (DEBUG, INFO, WARNING, ERROR, CRITICAL)')
 @click.option('--version', is_flag=True, help='Print version info')
+@click.version_option(version=__version__, message='%(prog)s %(version)s')
+@click.pass_context
 def cli(log_level, version):
     setup_logger(
         level=log_level.upper()
     )
 
-    if version:
-        print('vcspull %s' % __version__)
-        return
-
 
 @click.command(name='update')
 @click.argument('repos', nargs=-1)