So when I login (using github), it offers me two accounts: certik and isuruf. The certik account which I use doesn't have admin for your repo, but the isuruf account allows me to see your repositories (?) including having the admin rights for the repo above.
In each project you have, VIEW, RUN BUILD, UPDATE SETTINGS, DELETE PROJECT. I have permissions for VIEW, RUN BUILD in symengine.rb which is enough. For symengine I have VIEW, RUN BUILD, UPDATE SETTINGS
I don't think appveyor makes any distinguish between who made the PR