Add files in tmp/compiled_package_cache folder and old warden stemcell archive to .gitignore

After running `provision_cf` script I see lots of untracked files in `tmp/compiled_package_cache` folder. is it ok? Also after running `provision_cf` several times I've got latest-bosh-stemcell-warden.tgz.old file untracked. Think they can be added to gitignore.