Test and REPL to work with *nix.

I was doing a quick test on the new REPL commands and found some things
This PR has a couple of fixes ... this was done kind of quick so ... sorry.

1) Had some "Warning as errors" when compiling.  Removed unused "var result =" on tests.

2) Removed if (!path.EndsWith(@"\")) ... as Path.Combine takes care of this, so we should not need this. And if we do we should use Path.DirectorySeparatorChar to support *nix

3) Fix test in Script.Core.Test so they pass on *nix env as well.  Used %HOME path instead of "C:\". 

Other test projects might need to be tested as well.  I might add them later or a new PR.

Happy Friday.