Issue #53: Add probot/stale bot configuration to ID and close stale issues.

.github/stale.yml

@@ -0,0 +1,60 @@
+---
+# Configuration for probot-stale - https://github.com/probot/stale
+
+# Number of days of inactivity before an Issue or Pull Request becomes stale
+daysUntilStale: 90
+
+# Number of days of inactivity before an Issue or Pull Request with the stale
+# label is closed. Set to false to disable. If disabled, issues still need to be
+# closed manually, but will remain marked as stale.
+daysUntilClose: 30
+
+# Only issues or pull requests with all of these labels are check if stale.
+# Defaults to `[]` (disabled)
+onlyLabels: []
+
+# Issues or Pull Requests with these labels will never be considered stale. Set
+# to `[]` to disable
+exemptLabels:
+  - pinned
+  - security
+  - planned
+  - priority/critical
+  - verified
+
+# Set to true to ignore issues in a project (defaults to false)
+exemptProjects: false
+
+# Set to true to ignore issues in a milestone (defaults to false)
+exemptMilestones: true
+
+# Set to true to ignore issues with an assignee (defaults to false)
+exemptAssignees: false
+
+# Label to use when marking as stale
+staleLabel: lifecycle/stale
+
+# Limit the number of actions per hour, from 1-30. Default is 30
+limitPerRun: 30
+
+pulls:
+  markComment: |-
+    PRs go stale after 90 days of inactivity.
+    If there is no further activity, the PR will be closed in another 30 days.
+
+  unmarkComment: >-
+    This pull request is no longer stale.
+
+  closeComment: >-
+    This pull request has been closed due to inactivity.
+
+issues:
+  markComment: |-
+    Issues go stale after 90 days of inactivity.
+    If there is no further activity, the issue will be closed in another 30 days.
+
+  unmarkComment: >-
+    This issue is no longer stale.
+
+  closeComment: >-
+    This issue has been closed due to inactivity.