Pin GitHub Actions to full-length commit SHAs (#897)

Author: danfiedler-msft

.github/dependabot.yml

@@ -0,0 +1,11 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    groups:
+      github-actions:
+        patterns: ["*"]
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7

.github/workflows/nodejs.yml

@@ -16,9 +16,9 @@ jobs:
         node-version: [10.x]
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@50fbc622fc4ef5163becd7fab6573eac35f8462e # v1.2.0
     - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@f1f314fca9dfce2769ece7d933488f076716723e # v1.4.6
       with:
         node-version: ${{ matrix.node-version }}
     - name: Deploy Pages 

.github/workflows/stale.yml

@@ -11,7 +11,7 @@ jobs:
   stale:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/stale@v8
+      - uses: actions/stale@1160a2240286f5da8ec72b1c0816ce2481aabf84 # v8.0.0
         with:
           stale-issue-message: "This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 30 days."
           stale-pr-message: "This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 30 days."