User is warned when using `--replace`

[jvanderhoof]

As a person making changes to policy, I want to be warned that when I use --replace, I will be destroying the existing policy, so that I reduce my chance of making a really bad mistake.

GIVEN a Conjur master, the CLI, and valid credentials WHEN I run:

$ conjur policy load --replace root root.yml

THEN I receive the following message:

This command will replace the entire contents of policy "root". Are you sure you want to proceed? (Yes/No)

AND if I type "Yes" THEN the command will run as expected AND if I type "No" THEN the command will exit with no action AND if I add the flag --force or -f THEN I will not be asked to confirm and the command will run as expected