added pre push hook for linter

package.json

@@ -7,6 +7,7 @@
     "build": "babel src --out-dir build",
     "dev": "NODE_ENV=dev webpack-dev-server --inline --hot --config example/webpack.js",
     "lint": "eslint src/**/*.js",
+    "postinstall": "mkdir -p .git/hooks && echo 'npm run lint' > .git/hooks/pre-push && chmod +x .git/hooks/pre-push",
     "prepublish": "npm run build",
     "test": "jest",
     "test:watch": "npm run test -- --watch",