Tweak what happens when run on non-Windows platforms: set install prefix as well as scheme, and don't convert all installation paths (that's now done by the "install" command for us).
Tweak what happens when run on non-Windows platforms: set install prefix
as well as scheme, and don't convert all installation paths (that's now
done by the "install" command for us).

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator