Fixes issue with backbone version 1.2.1 and failed gulp
Fixes issue with backbone version 1.2.1 and failed gulp

Before
```
➜  auth0-roles-permissions-dashboard-sample git:(master) gulp build
[18:55:20] Using gulpfile ~/Documents/auth0/auth0-roles-permissions-dashboard-sample/gulpfile.js
[18:55:20] Starting 'build'...
[18:55:20] Starting 'clean'...
[18:55:20] Finished 'clean' after 6.4 ms
[18:55:20] Starting 'css'...
[18:55:20] Starting 'js'...
[18:55:20] Bundling scripts...
[18:55:23] 'css' styles.css 164.73 kB
[18:55:23] Finished 'css' after 2.92 s
[18:55:23] Starting 'css-minify'...
[18:55:26] 'css-minify' styles.min.css 130.87 kB
[18:55:26] Finished 'css-minify' after 2.93 s
[18:55:30] { [Error: Cannot find module 'jquery' from '/Users/dschenkelman/Documents/auth0/auth0-roles-permissions-dashboard-sample/node_modules/backbone']
  stream: 
   { _readableState: 
      { highWaterMark: 16,
        buffer: [],
        length: 0,
        pipes: [Object],
        pipesCount: 1,
        flowing: true,
        ended: false,
        endEmitted: false,
        reading: true,
        sync: false,
        needReadable: true,
        emittedReadable: false,
        readableListening: false,
        objectMode: true,
        defaultEncoding: 'utf8',
        ranOut: false,
        awaitDrain: 0,
        readingMore: false,
        decoder: null,
        encoding: null,
        resumeScheduled: false },
     readable: true,
     domain: null,
     _events: 
      { end: [Object],
        error: [Object],
        data: [Function: ondata],
        _mutate: [Object] },
     _maxListeners: undefined,
     _writableState: 
      { highWaterMark: 16,
        objectMode: true,
        needDrain: false,
        ending: true,
        ended: true,
        finished: true,
        decodeStrings: true,
        defaultEncoding: 'utf8',
        length: 0,
        writing: false,
        corked: 0,
        sync: false,
        bufferProcessing: false,
        onwrite: [Function],
        writecb: null,
        writelen: 0,
        buffer: [],
        pendingcb: 0,
        prefinished: true,
        errorEmitted: false },
     writable: true,
     allowHalfOpen: true,
     _options: { objectMode: true },
     _wrapOptions: { objectMode: true },
     _streams: [ [Object] ],
     length: 1,
     label: 'deps' } }
```
auth0/auth0-roles-permissions-dashboard-sample,darbio/auth0-roles-permissions-dashboard-sample,auth0/auth0-roles-permissions-dashboard-sample,darbio/auth0-roles-permissions-dashboard-sample,darbio/auth0-roles-permissions-dashboard-sample,auth0/auth0-roles-permissions-dashboard-sample