meta: adding aabmass as approver (#941)

once approved the PR, aabmass will be added to the approvers team

Author: alrex

README.md

@@ -103,6 +103,7 @@ Meeting notes are available as a public [Google doc](https://docs.google.com/doc
 
 Approvers ([@open-telemetry/python-approvers](https://github.com/orgs/open-telemetry/teams/python-approvers)):
 
+- [Aaron Abbott](https://github.com/aabmass), Google
 - [Carlos Alberto Cortez](https://github.com/carlosalberto), Lightstep
 - [Tahir H. Butt](https://github.com/majorgreys) DataDog
 - [Chris Kleinknecht](https://github.com/c24t), Google