Error compiling version 2

```
C:\Users\JC\Desktop\material-design-lite-2-components-poc>gulp
[03:12:38] Requiring external module babel-register
[03:12:39] Using gulpfile ~\Desktop\material-design-lite-2-components-poc\gulpfile.babel.js
[03:12:39] Starting 'clean'...
[03:12:39] Finished 'clean' after 21 ms
[03:12:39] Starting 'default'...
[03:12:39] Starting 'styles'...
[03:12:39] Starting 'styles-grid'...
[03:12:40] styles-grid all files 17.77 kB
[03:12:40] Finished 'styles-grid' after 989 ms
[03:12:41] styles all files 1.06 MB
[03:12:41] Finished 'styles' after 2.09 s
[03:12:41] Starting 'lint:sources'...
[03:12:42] Finished 'lint:sources' after 864 ms
[03:12:42] Starting 'scripts'...

stream.js:74
throw er; // Unhandled stream error in pipe.
^
Error
at new JS_Parse_Error (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :1526:18)
at js_error (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :1534:11)
at croak (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2026:9)
at token_error (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2034:9)
at unexpected (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2040:9)
at semicolon (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2060:56)
at simple_statement (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2240:73)
at eval (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2113:19)
at eval (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2073:24)
at block_ (eval at (C:\Users\JC\Desktop\material-design-lite-2-components-poc\node_modules\uglify-js\tools\node.js:22:1), :2353:20)
```

gulp all && gulp serve has the same error.

Platform: Windows 10
Node: 5.6.0
Gulp: 3.9.1