Fixes the --tags argument for service_checks in dogshell (#387)

* Fixes the --tags argument for service_checks in dogshell

* strip when checking if truthy

datadog/dogshell/service_check.py

@@ -31,9 +31,13 @@ def setup_parser(cls, subparsers):
     def _check(cls, args):
         api._timeout = args.timeout
         format = args.format
+        if args.tags:
+            tags = sorted(set([t.strip() for t in args.tags.split(',') if t.strip()]))
+        else:
+            tags = None
         res = api.ServiceCheck.check(
             check=args.check, host_name=args.host_name, status=int(args.status),
-            timestamp=args.timestamp, message=args.message, tags=args.tags)
+            timestamp=args.timestamp, message=args.message, tags=tags)
         report_warnings(res)
         report_errors(res)
         if format == 'pretty':