Fix CSV export on Windows

csv.reader() already generates \r\n line endings on Windows, so tell
open() not to convert those \n's into more \r\n's, which would produce
\r\r\n line endings.

gitlab_jobs.py

@@ -207,7 +207,7 @@ def main():
 
     if args.csv:
         print("\nWriting {filename}...".format(filename=args.csv))
-        with open(args.csv, 'w') as f:
+        with open(args.csv, 'w', newline='') as f:
             writer = csv.writer(f)
             for job_name, durations in sorted(job_durations.items()):
                 writer.writerow([job_name] + durations)