Qualichat

- Some badges were added to README.
- Documentation has been updated.
- Added return type for `generate_graph` function.

- `README.md` updated
- Fixed a bug where reading the internal book file threw a `UnicodeError`.

- Minimum Python version was downgraded to Python 3.7.1.
- The `Message` interface data was renamed from `Qntd_Caract_<name>` to `Qty_char_<name>`.
- `GraphGenerator.users_activity` has been properly documented.
- `matplotlib` legends has been fixed.
- `GraphGenerator.users_messages_aspects` was added.
- `GraphGenerator.message_sub_period` was added.
- Logging messages has been added.
- `GraphGenerator.message_marks` was added.
- `GraphGenerator.GraphGenerator.messages_per_weekday` was added.
- `GraphGenerator.GraphGenerator.messages_components` was added.
- `GraphGenerator.users_messages_marks` was added.

Qualichat v1.1.0 has been released.

- Models has been rewrited.
- Graphs generators has been rewrited.

First release of Qualichat.