Release v0.5.3

What's Changed

• feat(schema): link to schema documentation index (cosmetic change) by @sanjayankur31 in #170
• numpy should be an explicit requirement by @pgleeson in #171
• To v0.5.3; uses setup.cfg; tested on mac & win too by @pgleeson in #174
• Chore/remove setup.py by @sanjayankur31 in #173

Full Changelog: v0.5.1...v0.5.3