Dictdatabase

- Add automatic key indexing for more performance when doing partial reads and writes

- Drop unused brotli dependency

- Raise test coverage to 96%

- Same fix as in 2.0.1 but for the relative key nesting counter

- Fix parsing issue when a string ends with a backslash (Now conformant to JSON spec https://www.json.org/json-en.html)

v.1.3.0
- Improve locking mechanism. In case of heavy write access to one file, the read operations will not be delayed anymore

- Add config options for custom encoder and decoder
- Rewritten testing suite
- Minor code improvements