Merge pull request #66 from StudyLions/rewrite

Merge branch 'master' into rewrite

fix(ranks): Fix notification logic.

feat(skins): Implement CustomSkin editor.

feat(skins): Implement user skin ui.

chore: Update requirements.

feat(skins): Apply skins to graphics.

feat(skins): Implement custom skin backend.

fix(schema): Fix timer column typo.

(core): Add explicit cog type overloads.

feat(bot): Impl global dispatch over shardtalk.

Merge branch 'feature-premium' into rewrite

feat(premium): Ad-whitelist premium guilds.

feat(premium): Impl guild upgrade path.

feat(premium): Implement gem API and admin.