I tried to run a jasmine unit test in resharper 7 in vs2012 but its failing.
No, you can't change the url. But what is causing your test to fail is most likely a missing file reference. What you can do is to debug the test and check the loaded file references and see what is missing:
Resharper -> Options -> Tools -> Unit Testing -> JavaScript Tests -> Run Tests with...
jasmine.getEnv().currentRunner().finishCallback = function () { };
This will override the finishCallback
function which is called to notify Resharper about test being finished, so the test wil run forever and you can refresh it by hitting F5 and debug indefinitely. You only must stop the test manually then in Resharper's Unit Test Sessions window.