Do not use namespace in url paths pre v1beta3 from client

Fixes #3062 

The major change here is to just get the test cases now smart enough to know what type of url to look for based on the testapi.Version() so things will work when we run testapi.Version == v1beta3 like they used to.

FYI @lavalamp @smarterclayton 
Nit: "namespaceInPath"?