[GHA] Update CI script to use main branch instead of master (#420)

.github/workflows/ci.js.yml

@@ -1,20 +1,20 @@
 # This workflow will do a clean install of node dependencies and run tests across different versions of node
 # For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
 
-name: typescript / master
+name: typescript / main
 
 on:
   push:
-    branches: [master]
+    branches: [main]
 
 jobs:
   precheck:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f # v2.3.4
       - name: Use Node.js LTS (14.x)
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@46071b5c7a2e0c34e49c3cb8a0e792e86e18d5ea # v2.1.5
         with:
           node-version: 14.x
 
@@ -32,9 +32,9 @@ jobs:
         node-version: [12.x, 14.x, 15.x]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f # v2.3.4
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@46071b5c7a2e0c34e49c3cb8a0e792e86e18d5ea # v2.1.5
         with:
           node-version: ${{ matrix.node-version }}