create ci-task for eslint (#77)

* Create nodejs.yml

.github/workflows/nodejs.yml

@@ -0,0 +1,23 @@
+name: Node.js CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+    - run: npm run lint
+      env:
+        CI: true

package.json

@@ -61,7 +61,7 @@
     "serve": "gatsby serve",
     "clean": "gatsby clean",
     "test": "echo \"Write tests! -> https://gatsby.dev/unit-testing\" && exit 1",
-    "lint": "eslint --fix src"
+    "lint": "eslint src"
   },
   "repository": {
     "type": "git",