Make npm-run-all silent

Author: developit

package.json

@@ -11,7 +11,7 @@
     "testonly": "mocha --compilers js:babel-register test/**/*.js",
     "lint": "eslint src test",
     "test": "flow && npm run lint && npm run testonly",
-    "build": "npm-run-all clean -p rollup -p minify:* -s docs size",
+    "build": "npm-run-all --silent clean -p rollup -p minify:* -s docs size",
     "clean": "rimraf dist",
     "rollup": "rollup -c",
     "minify:cjs": "uglifyjs $npm_package_main -cm toplevel -o $npm_package_main -p relative --in-source-map ${npm_package_main}.map --source-map ${npm_package_main}.map",