Add PSWindows hosts to beaker acceptance tests

The current acceptance host matrix for beaker acceptance only includes Windows machines that have Cygwin preloaded. We should add hosts that are also PSWindows, but, we can't do that very simply right now because there are many assumptions in the tests that assume we have cygwin loaded already. So, there are two aspects of this ticket that should be done:

1) Fix the beaker acceptance tests in the base folder to not make the assumption that Cygwin is loaded
2) Actually add the host configuration to the acceptance matrix

Additionally, we could also cover bitvise boxes here as well, effectively getting both bitvise and PSWindows coverage with one additional host in the matrix. If for some reason we cannot add bitvise coverage at the same time as PSWindows coverage, we should make a separate ticket for that.