Add application/json to bakery _interact to support issue with identity.
Add application/json to bakery _interact to support issue with identity.

bac/juju-gui,mitechie/juju-gui,bac/juju-gui,bac/juju-gui,mitechie/juju-gui,mitechie/juju-gui,mitechie/juju-gui,bac/juju-gui