use FileUtils for withEnvironment because it works

I couldn't pinpoint why it does it, but when using `withEnvironment(path(... getResource("environment")))` in maestro the `copyFromLocal` op would create `${dir}/user/environment/source/..` instead of `${dir}/user/source/..`

It only did this if you ran the whole test suite though.. so.. urgh. I couldn't replicate this issue in a unit test.
FileUtils works correctly.