Using cross-env instead of pure environment variable specification to make it work on windows.

packages/server/package.json

@@ -36,7 +36,7 @@
     "test:integration": "jest routes --runInBand",
     "test:watch": "jest --watch",
     "run:docker": "node src/index",
-    "dev:builder": "PORT=4001 nodemon src/index.js",
+    "dev:builder": "cross-env PORT=4001 nodemon src/index.js",
     "electron": "electron src/electron.js",
     "build:electron": "electron-builder --dir",
     "publish:electron": "electron-builder -mwl --publish always",
@@ -106,6 +106,7 @@
   },
   "devDependencies": {
     "@jest/test-sequencer": "^24.8.0",
+    "cross-env": "^7.0.3",
     "electron": "10.1.3",
     "electron-builder": "^22.9.1",
     "electron-builder-notarize": "^1.1.2",