Update Marionnette version to avoid Backbone conflicts (bis)

[misstick]

See previous PR : https://github.com/cozy/cozy-proxy/pull/302

You will find history and complete description of the issue here: https://github.com/marionettejs/backbone.marionette/issues/2559#issuecomment-106037738

There was missing webpack configuration to link to the right path when calling package backbone or marionette

[gregorylegarec]

Thanks @misstick