remove postinstall script

Author: dmitry-korolev

package.json

@@ -24,8 +24,7 @@
     "pretest": "npm run build",
     "test": "mocha --compilers js:buble/register",
     "posttest": "npm run lint",
-    "prepublish": "npm run test",
-    "postinstall": "npm i && npm run build"
+    "prepublish": "npm run test"
   },
   "dependencies": {
     "compare-versions": "2.0.1",