Add issue robot

.github/stale.yml

@@ -0,0 +1,33 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 180
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 7
+# Issues with these labels will never be considered stale
+exemptLabels:
+    - good first issue
+    - contribution welcome
+    - dependencies
+    - kind/bug
+    - kind/code quality
+    - kind/enhancement
+    - kind/performance
+    - kind/proposal
+    - kind/refactor
+    - kind/user experience
+    - Soc2019
+    - SoC2020
+# Label to use when marking an issue as stale
+staleLabel: expired
+# Comment to post when marking an issue as stale. Set to `false` to disable
+markComment: >
+    Thanks for your feedback and contribution. But the issue/pull request has
+    not had recent activity more than **180 days**. This issue/pull request will
+    be closed if no further activity occurs **7 days later**.
+
+    We may solve this issue in new version. So can you upgrade to newest version
+    and retry?
+
+    If there are still issues or want to contribute again. Please create new issue
+    or pull request again.
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: false