fix(package): update browserify to version 15.0.0

Author: greenkeeper[bot]

package.json

@@ -35,7 +35,7 @@
     "babel-preset-env": "^1.6.1",
     "babel-preset-react": "^6.24.1",
     "babelify": "^8.0.0",
-    "browserify": "^14.5.0",
+    "browserify": "^15.0.0",
     "fsify": "^2.0.4",
     "loose-envify": "^1.3.1",
     "uglify-js": "^3.1.6",