Clean up clean step

Author: bcomnes

package.json

@@ -10,10 +10,10 @@
     "prestart": "run-s build",
     "version": "run-s release",
     "prepublish": "run-s build",
-    "build": "rimraf build && mkdirp build && run-p build:*",
+    "build": "run-p build:*",
     "build:bundle": "cross-env NODE_ENV=production webpack --config webpack.config.babel.js",
     "build:umd": "cross-env NODE_ENV=production webpack --config webpack.umd.config.babel.js",
-    "prebuild": "mkdirp build",
+    "prebuild": "rimraf build && mkdirp build",
     "test": "eslint src",
     "release": "node ./script/release.js",
     "format": "prettier --write 'src/**/*.js'",