Togglcli

Features:
* Python 3.8 support
* new `toggl sum` command that displays sums of time grouped by days
* new `toggl goal` command that waits until you reach your defined goal for the day and the send notification
* new theming support
* `--today` flag for `ls` and `sum` command

Features:
* New Tag model with CLI commands
* 'me' command to display current user's info

Fixes:
* Correct retrieval of package's version
* Properly working Premium/Non-premium tests

Fixes for python_required and calculation of duration

Fix for required python version

Full rewrite of the tool by [AuHau](https://github.com/AuHau), which implements most of the toggl's API capabilities.
Entities which is now possible to fully manage (eq. CRUD operations):
* Time entries
* Clients
* Projects
* Project users
* Tasks (only for premium workspaces)
* Workspaces
* Workspace users

Main new features of the tool:
* Possibility to use environment variables to specify some of the input parameters
* Possibility to specify different config to be used for the command's execution
* Django ORM's like API Classes

* Fixing bootstrap failures
* Dropping relative imports
* Minor improvements