We’re not using Heroku anyway
Minor clarifications to README
Move database config to ENV 

- You can run migrations with `lein migrate` or `lein rollback [n]`
Remove unneeded exception serialisation 

— now provided by lib-noir
Minor cleanup
[WIP] User login & registration 

- Users can login / logout
- Users can register
- Users have a profile 

TODO: 
- CSRF token validation 
- Some extra design 
- Better top-bar management 
- … persistence and retrieval of PDFs + annotations