Revert "better mocking of stdout.tty? / .enable_paging"

This reverts commit 3cd70d52cbbdb3896d7fe625171ec8a85b57359a.
Revert "fixed paging mock and added a verifier spec"

This reverts commit b2f6c041fc34a3539cb8823c0a0eff4074190010.
mocked Commander::UI.enable_paging