Fix #770 - Return memory and swap (real) size in JSON

Fix #770 - Return memory and swap (real) size in JSON

`App` object is made with the sum between requested swap and requested memory (due to docker that needs swap including memory). The returned json has the real swap size (swap - memory) so tests take care of this and check for the real swap size and not the size wrote on App object.

Probably this could be done better in a next release