Tag roster-related XEPs

[avidseeker]

See: https://wiki.xmpp.org/web/Roster for more info

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[avidseeker]

I agree.

Signed.

• Avid Seeker