Pipeline REST adapter save/update does not send data

My REST adapter integration tests are failing against aerogear.js 1.3.0 dev. However they pass when running them against the aerogear.js 1.2.0 version.

Issue:
When using the pipeline rest save/update then an empty JSON is sent to the defined endpoint instead of the model's data. For instance in the below example, an empty JSON is sent instead of sending a JSON with the description,

e.g:
save = saveMemberPipe.save({
description: "description_2"
}

Reproduce:
Build the aerogear js version 1.3.0 dev.
Replace the aerogear.js dev version of the https://github.com/aerogear/aerogear-js-integration repo with the latest one
Get the PULL request: https://github.com/aerogear/aerogear-js-integration/pull/4
Execute: ./servers/jboss-as/setup.sh
Execute: grunt integration-jbossas

For debugging with firefox, you can start manually the jboss-as which is already configured by the grunt-jboss-as plugin and then open the QUnit tests.

The debugging shows that the JSON stringify (line https://github.com/aerogear/aerogear-js/blob/master/src/pipeline/adapters/rest.js#L542) of the extraOptions.data is empty. My sense is that the problem is related to the formData https://github.com/aerogear/aerogear-js/blob/master/src/pipeline/adapters/rest.js#L514 block. If I remove this block, the data are sent correctly to the server.