Skip the overwrite check when either force or test is True
Add test flag to add_keypair test
Update tests to match the new behavior of does_host_have_location
Distinguish between 'openssl req' and 'openssl x509'
Override uncaught method calls

Some mocks (previous to 1ebe4b0) were matching every ssh call
that contained '/etc/appscale'. This matched more calls than the
stated check for that directory. This commit adds additional mocks
to cover those left uncaught by the update.