ansible: try to fix pycrypto build on 10.8

Tests whether adding ENV.refurbish_args (suggested at https://github.com/Homebrew/homebrew/pull/34682#issuecomment-65813603) allows pycrypto to build on 10.8; failure to build was originally reported at #34638. Does not address the root problem that Language::Python.setup_install doesn't invoke Formula#system.