Replace makeStubMethod with sinon.stub in the web handler tests.
Replace makeStubMethod with sinon.stub in the web handler tests.

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