You can uninstall or removes an installed ca-cacert package itself from Ubuntu 16.10 (Yakkety Yak) through the terminal,
$ sudo apt-get remove ca-cacert
If you would like to remove ca-cacert and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove ca-cacert
If you use with purge options to ca-cacert package all the configuration and dependent packages will be removed.
$ sudo apt-get purge ca-cacert
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove ca-cacert