Specify branches to trigger build (#201)

* Add build workflow

* Specify branches to trigger build action

Author: elo80ka

.github/workflows/build.yml

@@ -2,9 +2,11 @@ name: Run tests and prepare release 🚀
 
 on:
   push:
-    branches: [ $default-branch ]
+    branches:
+      - master
   pull_request:
-    branches: [ $default-branch ]
+    branches:
+      - master
 
 jobs:
   build: