Get an environment object for a given environment name

[jamesramsden-bh]

It should be possible to query the location of a python.exe path for a virtual environment's name without the burden of calling the InstallVirtualenv method.

This method will be very lightweight - it will only construct the path where python.exe should live, based upon an environment name, and will not attempt to install that environment.

If the resultant path does not exist, an error should be returned to the user that the environment does not exist, and to run the appropriate env installer again.