build: update actions versions (#18)

Author: lirantal

.github/workflows/main.yml

@@ -11,8 +11,8 @@ jobs:
     name: Node ${{ matrix.node }} (${{ matrix.platform }})
     runs-on: ${{ matrix.platform }}
     steps:
-      - uses: actions/checkout@v1
-      - uses: actions/setup-node@v1
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
         with:
           node-version: ${{ matrix.node }}
       - name: install dependencies
@@ -31,8 +31,8 @@ jobs:
     runs-on: 'ubuntu-latest'
     needs: build
     steps:
-      - uses: actions/checkout@v1
-      - uses: actions/setup-node@v1
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
         with:
           node-version: '12'
       - name: install dependencies