- reorganise files by a) grouping all gnucash books in a separate folder gnucash_books, b) extracted common file initialisation in tests into a test_helper
- add as integration tests the example scripts
- add tutorials
- clean some __init__ imports
- fix doc links (to point to master instead of latest)
- add slots testing and slots tutorial (draft)
- update tutorial on slots
- refactor kvp wrt name of keys
- improve testing of kvp
- updated script to retrieve projects from github
- upgrade version number
- enable test of scripts