Fix electronegativity workflow config

Signed-off-by: Sebastian Malton <sebastian@malton.name>

.github/workflows/electronegativity.yml

@@ -1,9 +1,11 @@
-on:
-  push:
-
 name: Electronegativity
 on:
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
 jobs:
   build_job:
     runs-on: ubuntu-latest
@@ -12,7 +14,7 @@ jobs:
 
       - uses: actions/setup-node@v2
         with:
-          node-version: '14'
+          node-version: "14"
 
       - uses: doyensec/electronegativity-action@v1.1
         with: