GWT polymer and Google App engine deploy

[Jenny Zilverberg]

We are building a new GWT module using GWT polymer. Our GWT version is 2.8.0-beta1 and vaadin-gwt-polymer-elements is 1.2.3.0 with Java 7 (Google app engine is not supporting Java 8 yet)

When compiling GWT (using maven) polymer library is using bower to install all it's dependencies and creates a bower_components folder in the final package. We are deploying to Google app engine and Prism bower component has invalid chars in his path, which causing the deploy to fail. We can remove this library with a script from being deployed or find another workaround but wondering if anyone else has experienced with deploying GWT using Polymer to Google app engine and has some better idea.