dependabot: check for github actions and bundler

Author: bastelfreak

.github/dependabot.yml

@@ -0,0 +1,17 @@
+version: 2
+updates:
+# raise PRs for gem updates
+- package-ecosystem: bundler
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "13:00"
+  open-pull-requests-limit: 10
+
+# Maintain dependencies for GitHub Actions
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "13:00"
+  open-pull-requests-limit: 10