Disable yum fastestmirror plugin on CentOS

The fastestmirror plugin may be useful at some points, but it can be a pain in the ass at others.
For example, I tried updating my CentOS installation today and because of the mirror caching it was downloading the updates at 30K/s. After disabling the plugin the speed from picking a different mirror jumped to 3MB/s.

To disable the plugin…