[vitrage] Nominating Ivan Kolodyazhny for Vitrage core

Hi, I would like to nominate Ivan Kolodyazhny for Vitrage core. Ivan has been contributing to Vitrage for a while now. He has focused on upgrade support, vitrage-dashboard and vitrage-tempest-plugin enhancements, and during this time gained a lot of knowledge and experience with Vitrage code base. I believe he would make a great addition to our team. Thanks, Ifat.