Add dependabot

Author: derek-etherton-opslevel

.github/workflows/dependabot.yml

@@ -0,0 +1,9 @@
+version: 2
+updates:
+  - package-ecosystem: 'bundler'
+    directory: '/'
+    open-pull-requests-limit: 10
+    schedule:
+      interval: 'weekly'
+    labels:
+      - "dependencies"