v3.0-alpha.3

What's Changed

• Update API docs by @iniyannatarajan in #26
• Change sphinx theme by @iniyannatarajan in #27
• Revert to classic theme by @iniyannatarajan in #28
• Clean up unused code by @iniyannatarajan in #29
• Remove pyfits dependency by @iniyannatarajan in #30
• Update documentation and setup.py by @iniyannatarajan in #31
• Update docs by @iniyannatarajan in #32
• Test sphinx rtd theme by @iniyannatarajan in #33
• Specify sphinx rtd theme in setup.py by @iniyannatarajan in #34
• Add requirements for rtd by @iniyannatarajan in #35
• Debug autodoc generation for API documentation by @iniyannatarajan in #36
• Restructure code and update API docs by @iniyannatarajan in #37
• Fix import in setup.py by @iniyannatarajan in #38

Full Changelog: v3.0.0-alpha.2...v3.0-alpha.3