Please add PexpectLibrary to LIBRARIES> EXTERNAL #206

Hi,

I am the maintainer of PexpectLibrary and I would like to request that you add PexpectLibrary to the robotframework page.

Here's the information.

Name of the library: PexpectLibrary
Short description: An (almost) complete and convenience Pexpect wrapper for Robot Framework, with extra functionalities.
Link: https://github.com/lipan-sudo/PexpectLibrary/

Thanks,

pan li