setting env with NODE_ENV

.gitignore

@@ -1,4 +1,5 @@
 /out
 .next
 node_modules
-.DS_Store
+.DS_Store
+yarn.lock

README.md

@@ -9,4 +9,4 @@ ETHPrize single page React website
 
 `npm run deploy` to deploy to `https://nona-creative.github.io/ETHPrize`
 
-`yarn lint` runs the eslinter
+`npm lint` runs the eslinter

next.config.js

@@ -1,7 +1,10 @@
-const withSass = require('@zeit/next-sass')
+const withSass = require('@zeit/next-sass');
+
+const dev = process && process.env && process.env.NODE_ENV === 'development';
+
 module.exports =
   withSass({
-    assetPrefix: isProduction ? '/ETHPrize' : '',
+    assetPrefix: dev ? '' : '/ETHPrize',
     exportPathMap: function(defaultPathMap) {
       return {
         '/': { page: '/' }