chore: avoid build run-scripts on local npm install (#255)

* chore: avoid build run-scripts on local npm install
* style: avoid unnecessary echo

Author: marionebl

package.json

@@ -8,7 +8,7 @@
     "commit": "node bin/git-cz",
     "build": "babel src --out-dir dist",
     "build:watch": "babel --watch src --out-dir dist",
-    "prepublish": "npm run build",
+    "prepublish": "not-in-install && npm run build || true",
     "report-coverage": "nyc report --reporter=lcov | codecov",
     "semantic-release": "semantic-release pre && npm publish && semantic-release post",
     "start": "npm run test:watch",
@@ -54,6 +54,7 @@
     "chai": "3.5.0",
     "codecov.io": "0.1.6",
     "ghooks": "1.2.4",
+    "in-publish": "^2.0.0",
     "mocha": "2.5.3",
     "node-uuid": "1.4.7",
     "nodemon": "1.9.2",