gulp-uglify errors with latest async and locatecontrol

[nrenner]

"async": "~3.2.0",

GulpUglifyError: unable to minify JavaScript
Caused by: SyntaxError: Name expected
File: /home/norbert/Entwicklung/github/brouter-web/node_modules/async/dist/async.js
Line: 51
Col: 21

"leaflet.locatecontrol": "^0.76.0",

GulpUglifyError: unable to minify JavaScript
Caused by: SyntaxError: Invalid assignment
File: /home/norbert/Entwicklung/github/brouter-web/node_modules/leaflet.locatecontrol/src/L.Control.Locate.js
Line: 26
Col: 67

[tbsmark86]

That seems like the build problem i had with #641 Gulp can't handle modern javascript you need to extend the babel.config.js to not exclude those modules.

Or change the uglify to something that can handle es6+ maybe this SO-Answer will help.