Move OpenEdXInstanceQuerySet to the abstract GitHubInstance model
Move OpenEdXInstanceQuerySet to the abstract GitHubInstance model

brousch/opencraft,brousch/opencraft,open-craft/opencraft,omarkhan/opencraft,open-craft/opencraft,omarkhan/opencraft,omarkhan/opencraft,brousch/opencraft,open-craft/opencraft,omarkhan/opencraft,open-craft/opencraft,open-craft/opencraft