Merge pull request #475 from kenhys/use-v3-action

Migrate to use GitHub v3 action

Author: ashie

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: 'github-actions'
+    directory: '/'
+    schedule:
+      interval: 'monthly'

.github/workflows/linux.yml

@@ -17,7 +17,7 @@ jobs:
           - ubuntu-latest
     name: Ruby ${{ matrix.ruby }} unit testing on ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}