[git-cl] Lint and clean-up git-cl, test, and related modules

In this CL:
 - Clarify some comments.
 - Remove some unused imports.
 - Make some style more consistent (e.g. quotes, whitespace)

Tools used: pyflakes, flake8 (most warnings ignored)

Change-Id: Ibfb6733c8d844b3c75a7f50b4f3c1d43afabb0ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1773856Reviewed-by: Andrii Shyshkalov <tandrii@google.com>
Commit-Queue: Quinten Yearsley <qyearsley@chromium.org>

gerrit_client.py

@@ -19,14 +19,11 @@ import sys
 import urllib
 import urlparse
 
-from third_party import colorama
 import fix_encoding
 import gerrit_util
 import setup_color
 
 __version__ = '0.1'
-# Shortcut since it quickly becomes redundant.
-Fore = colorama.Fore
 
 
 def write_result(result, opt):
@@ -47,6 +44,7 @@ def CMDbranchinfo(parser, args):
   logging.info(result)
   write_result(result, opt)
 
+
 @subcommand.usage('[args ...]')
 def CMDbranch(parser, args):
   parser.add_option('--branch', dest='branch', help='branch name')
@@ -124,7 +122,7 @@ class OptionParser(optparse.OptionParser):
 def main(argv):
   if sys.hexversion < 0x02060000:
     print('\nYour python version %s is unsupported, please upgrade.\n'
-          %(sys.version.split(' ', 1)[0],),
+          % (sys.version.split(' ', 1)[0],),
           file=sys.stderr)
     return 2
   dispatcher = subcommand.CommandDispatcher(__name__)

gsutil.py

@@ -86,6 +86,7 @@ def temporary_directory(base):
     if os.path.isdir(tmpdir):
       shutil.rmtree(tmpdir)
 
+
 def ensure_gsutil(version, target, clean):
   bin_dir = os.path.join(target, 'gsutil_%s' % version)
   gsutil_bin = os.path.join(bin_dir, 'gsutil', 'gsutil')
@@ -183,5 +184,6 @@ def main():
   return run_gsutil(args.force_version, args.fallback, args.target, args.args,
                     clean=args.clean)
 
+
 if __name__ == '__main__':
   sys.exit(main())