fix setting environment variable on Windows

fixes #2

Author: endel

test/server/package.json

@@ -4,7 +4,7 @@
   "description": "Simple game server with Colyseus framework",
   "main": "index.js",
   "scripts": {
-    "start": "DEBUG=* ./node_modules/.bin/supervisor -i node_modules -- index.js"
+    "start": "cross-env DEBUG=* ./node_modules/.bin/supervisor -i node_modules -- index.js"
   },
   "author": "Loïc Guglielmino",
   "license": "MIT",
@@ -13,6 +13,7 @@
   },
   "devDependencies": {
     "supervisor": "^0.12.0",
-    "debug-logger": "^0.4.1"
+    "debug-logger": "^0.4.1",
+    "cross-env": "^5.0.0"
   }
 }