Upgrade to GitHub-native Dependabot

.github/dependabot.yml

@@ -0,0 +1,55 @@
+version: 2
+updates:
+- package-ecosystem: npm
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "08:00"
+  open-pull-requests-limit: 99
+  ignore:
+  - dependency-name: eslint-config-prettier
+    versions:
+    - 7.2.0
+    - 8.0.0
+    - 8.1.0
+    - 8.2.0
+  - dependency-name: eslint
+    versions:
+    - 7.18.0
+    - 7.19.0
+    - 7.20.0
+    - 7.21.0
+    - 7.22.0
+    - 7.23.0
+    - 7.24.0
+  - dependency-name: acorn
+    versions:
+    - 8.0.5
+    - 8.1.0
+    - 8.1.1
+  - dependency-name: y18n
+    versions:
+    - 4.0.1
+    - 4.0.2
+  - dependency-name: firebase-admin
+    versions:
+    - 9.4.2
+    - 9.5.0
+    - 9.6.0
+  - dependency-name: husky
+    versions:
+    - 4.3.8
+    - 5.0.9
+    - 5.1.0
+    - 5.1.1
+    - 5.1.2
+    - 5.1.3
+    - 5.2.0
+  - dependency-name: mocha
+    versions:
+    - 8.2.1
+    - 8.3.0
+    - 8.3.1
+  - dependency-name: eslint-plugin-prettier
+    versions:
+    - 3.3.1