Update build.yml

Author: EndBug

.github/workflows/build.yml

@@ -10,10 +10,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@master
+        uses: actions/checkout@v2
 
       - name: Set up Node.js
-        uses: actions/setup-node@master
+        uses: actions/setup-node@v1
         with:
           node-version: 12.x