Merge pull request #504 from transloadit/ci/single-build

ci: Remove duplicate build step

package.json

@@ -165,6 +165,6 @@
     "web:preview": "npm-run-all --parallel web:examples:watch web:bundle:update:watch web:serve",
     "web:update:frontpage:code:sample": "cd website && ./node_modules/.bin/hexo generate && cp -f public/frontpage-code-sample.html ./themes/uppy/layout/partials/frontpage-code-sample.html",
     "web": "npm-run-all web:clean web:build",
-    "prepublish": "npm-run-all clean build"
+    "prepublishOnly": "npm-run-all clean build"
   }
 }