chore: update actions/checkout to v2 (#146)

.github/workflows/test.yaml

@@ -10,13 +10,16 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        container: ["node:8", "node:10", "node:12", "node:14", "node:16"]
+        node: ["8", "10", "12", "14", "16"]
     runs-on: ubuntu-latest
-    container:
-      image: ${{ matrix.container }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
+
+      - name: Setup Node
+        uses: actions/setup-node@v2
+        with:
+          node-version: ${{ matrix.node }}
 
       - name: Install Dependencies
         run: npm install
@@ -29,18 +32,19 @@ jobs:
 
       - name: Report Coverage
         run: npm run codecov
-        if: ${{ matrix.container == 'node:14' }}
+        if: ${{ matrix.node == '14' }}
 
   browser-tests:
     runs-on: ubuntu-latest
     container:
       image: circleci/node:12-browsers
     steps:
-      - name: Checkout
-        uses: actions/checkout@v1
       - name: Permission Setup
         run: sudo chmod -R 777 /github /__w
 
+      - name: Checkout
+        uses: actions/checkout@v2
+
       - name: Install Dependencies
         run: npm install