chore: update github actions (#29)

Author: piotr-oles

.github/workflows/main.yml

@@ -4,10 +4,10 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
 
       - name: Setup node
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v2
         with:
           node-version: ${{ matrix.node }}
 
@@ -48,10 +48,10 @@ jobs:
         node: [14, 16]
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
 
     - name: Setup node
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: ${{ matrix.node }}
 
@@ -98,15 +98,15 @@ jobs:
         run: git fetch --unshallow --tags
 
       - name: Setup node
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v2
         with:
           node-version: 14
 
       - name: Get yarn cache
         id: yarn-cache
         run: echo "::set-output name=dir::$(yarn cache dir)"
 
-      - uses: actions/cache@v1
+      - uses: actions/cache@v2
         with:
           path: ${{ steps.yarn-cache.outputs.dir }}
           key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}