WIP: Functional tests

- [x] Setup intern
- [x] Test unauthenticated index
- [x] Test sign in
- [ ] Create mock device that responds to commands
- [ ] Bootstrapping script
- [ ] Test ring
- [ ] Test lock
- [ ] Test erase
- [ ] Extract constants.
I can haz copyrights?
(or we can create some other license for the files in the /tests/** folders if we don't want to use MPL2 for tests).