Skipping some of the tests closely tied to running in a
unix environment. Windows does not support chmod/chown
and this causes some tests to fail creating desired
behavior.
- `TestBuildWithInaccessibleFilesInContext`: uses chown/chmod
- `TestBuildDockerfileOutsideContext`: uses os.Symlink, not implemented on
windows
- `TestCpUnprivilegedUser`: uses chmod, and requires 'unprivilegeduser'
created by Dockerfile (and thus requires to run inside container)
- `TestBuildChownSingleFile`: uses chown
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
