Merge pull request #2391 from asbjornu/feature/stale-tweaks

Exempt issues from stalebot

Author: gep13

.github/stale.yml

@@ -7,6 +7,8 @@ exemptLabels:
   - pinned
   - security
   - bug
+  - failing test case
+  - help wanted
 # Label to use when marking an issue as stale
 staleLabel: stale
 # Comment to post when marking an issue as stale. Set to `false` to disable