astrofrog/sedfitter: v1.4

What's Changed Small astropy 4.0 compatibility refactor by @keflavich in https://github.com/astrofrog/sedfitter/pull/67 Update package infrastructure and fix compatibility with latest astropy versions by @astrofrog in https://github.com/astrofrog/sedfitter/pull/79 ndistances can't be a float in recent versions of numpy by @keflavich in https://github.com/astrofrog/sedfitter/pull/73 Use memmap when reading in model grids by @keflavich in https://github.com/astrofrog/sedfitter/pull/78 More infrastructure improvements by @astrofrog in https://github.com/astrofrog/sedfitter/pull/80 Full Changelog: https://github.com/astrofrog/sedfitter/compare/v1.3...v1.