I am trying to install tomcat 8 on centos 7. I am using the terminal as root. When I type in `source ~/.bashrc`, the terminal gives back the following error: `-bash: unalias: ls: not found`. 

**How can I resolve this error so that the `source ~/.bashrc` command can succeed?** 

Note that I recently added the line `unalias ls` as the last line of `~/.bashrc` as per [@Cyrus' solution to this other problem related to color aliasing in the same CentOS installation](https://unix.stackexchange.com/questions/212234/why-are-colors-mixed-up-in-centos-7-terminal).