WIP authors: base record

* Defines fields and models for author base record.
* Adds new function for jsonalchemy models definitions.
* Includes tests for author base record.

There is one thing to add here: We need to store the list of the publications. This is a relaton between an author and a publication and this directly touches the subject of monday's meeting.
In future we might write more complex architecture here. Perhaps every type will have its own class or even own file.