$ sudo apt-get remove fedmsg 

Uninstall fedmsg including dependent package

If you would like to remove fedmsg and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove fedmsg 

Use Purging fedmsg

If you use with purge options to fedmsg package all the configuration and dependent packages will be removed.

$ sudo apt-get purge fedmsg 

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 fedmsg 

See Also,