update GitHub workflow to lint before testing so lint errors don't hang

Author: terencehonles

.github/workflows/ci.yml

@@ -14,6 +14,7 @@ jobs:
       matrix:
         node-version: [8, 10, 12]
 
+    name: Test / Node ${{ matrix.node-version }}
     steps:
       - uses: actions/checkout@v2
         with:
@@ -27,5 +28,8 @@ jobs:
       - name: npm install
         run: npm install
 
+      - name: Lint
+        run: npx eslint src/
+
       - name: Run tests
         run: npm run test_ci