Reinstate dependabot (#86)

Author: johnboyes

.github/dependabot.yml

@@ -0,0 +1,18 @@
+---
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every weekday
+      interval: "daily"
+      labels:
+        - "dependencies"
+        - "patch"
+      reviewers:
+        - "johnboyes"