Attendance react

See closed PR for details: https://github.com/lifedispenser/djattendance/pull/1
see: `/requirements`. we have `base.txt`, `dev.txt` and `prod.txt`. Add the new packages to corresponding files. if its used across all deployments, but it in `base.txt`, otherwise, if it is development or production specific, put it in `dev.txt` or `prod.txt` 

we have a `requirements.txt` in `/` for heroku deployment purpose (it just redirects to `requirements/prod.txt`)