Added a functional test for starting a stopping with a different proxy port
Added a functional test for starting a stopping with a different proxy port

tjcunliffe/hoverfly,tjcunliffe/hoverfly,tjcunliffe/hoverfly,tjcunliffe/hoverfly,SpectoLabs/hoverfly,tjcunliffe/hoverfly,tjcunliffe/hoverfly,SpectoLabs/hoverfly