add dry-run option to install-system-deps
add dry-run option to install-system-deps

Summary: Useful to be able to see what packages would be installed without doing it, and to see rpm vs deb packages

Reviewed By: Croohand

Differential Revision: D32693528

fbshipit-source-id: a01257e7192f2f0299d57f6f8f7ee93452a6f3e4

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift