github workflow: assign name

https://github.com/fphammerle/ical2vdir/pull/2/commits/460a0de9beabca3c100d68071e53154e7345e870

.github/workflows/python.yml

@@ -1,5 +1,9 @@
 # sync with https://github.com/fphammerle/ical2vdir/blob/master/.github/workflows/python.yml
 
+# shown in badge
+# https://help.github.com/en/actions/automating-your-workflow-with-github-actions/configuring-a-workflow#adding-a-workflow-status-badge-to-your-repository
+name: tests
+
 on:
   push:
   pull_request: