clean up attendance-react

these are my proposed changes to cleanup `lifedispenser:attendance-react` before merging the pull request (https://github.com/attendanceproject/djattendance/pull/110/files). 
- [x] remove api-specific urlconf into it's own file
- [ ] delete comments and unused code
- [ ] update `requirements.txt` with React packages
- [ ] finalize `.jsx` strategy
- [ ] minify static assets