ServletMethodExecutor should get context path from container

While working on the JSR 88 container implementation, I noticed that ServletMethodExecutor is using the hard-coded context path "/test" to communicate with the application to invoke the ArquillianServletRunner. I think that the context path is something that the container implementation should be passing to the ServletMethodExecutor in the deploy() method.

This assumption poses a particular problem in the JSR 88 container. When a WAR is deployed using JSR 88, the module is assigned a random name, and hence a random context path. Since there is no way to override the context path "/test" used by the ServletMethodExecutor, it fails to communicate with the server.

The ServletMethodExecutor constructor should be changed to take the context path as the second parameter. All the container implementations will need to be updated accordingly.