update: adjust format

httprunner/cli.py

@@ -1,5 +1,6 @@
 # encoding: utf-8
 
+
 def main_hrun():
     """ API test: parse command line options and run commands.
     """
@@ -11,7 +12,7 @@ def main_hrun():
     from httprunner.compat import is_py2
     from httprunner.validator import validate_json_file
     from httprunner.utils import (create_scaffold, get_python2_retire_msg,
-                                prettify_json_file)
+                                  prettify_json_file)
 
     parser = argparse.ArgumentParser(description=__description__)
     parser.add_argument(