💚 Fixing CI Build

.travis.yml

@@ -15,6 +15,8 @@ language: node_js
 node_js:
   - "12"
 
+os: linux
+
 addons:
   apt:
     packages:

build.js

@@ -53,7 +53,7 @@ try {
 
     // Write version data into a file
     fs.writeFileSync(
-      PW_BUILD_DATA_DIR + "/version.json",
+      `${PW_BUILD_DATA_DIR}/version.json`,
       JSON.stringify(version)
     );
   })();