Merge pull request #303 from DeNA/feature/dependabot

add dependabot.yml

Author: srz-zumix

.github/dependabot.yml

@@ -0,0 +1,30 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    cooldown:
+      default-days: 7
+    groups:
+      actions-minor:
+        update-types:
+          - minor
+          - patch
+
+  - package-ecosystem: npm
+    directory: /
+    schedule:
+      interval: weekly
+    cooldown:
+      default-days: 7
+    groups:
+      npm-development:
+        dependency-type: development
+        update-types:
+          - minor
+          - patch
+      npm-production:
+        dependency-type: production
+        update-types:
+          - patch