feat(commit.py): throw an error if no token was supplied. i.e. empty variable.

A check is done on the supplied token,
if 'None', throws an error that can be viewed in the output log and
in the job output.

fixes #11 !12

conventional_commits/scripts/commit.py

@@ -26,6 +26,8 @@ for opt, arg in opts:
         print('[commit.py] -i <inputfile> -o <outputfile>')
         sys.exit()
     elif opt in ("-t", "--token"):
+       if arg is None:
+         raise ValueError('Token switch was specified, however no token was supplied.')
        ci_job_token = arg
     elif opt in ("-ti", "--title"):
        get_mr_title = True