Refactoring about i3-agenda

[matclab]

A quick browsing does not show me function needing refactoring because of complexity.
@rosenpin, do you have some in mind ?

[matclab]

Please tell me if you think something else shall be done.

Before taking maintenance, I'd also like to add more testing (I quickly began with human_delta which chocked:

    def test_human_delta():
        assert human_delta(dt.timedelta(0)) == "0m"
        assert human_delta(dt.timedelta(minutes=1)) == "1m"
>       assert human_delta(dt.timedelta(hours=1)) == "1h"
E       AssertionError: assert '0m' == '1h'
E         - 1h
E         + 0m

).

I'll open a new PR based upon #89 for tests.

[rosenpin]

Great find
I'll look into the PR and comment on everything once I get a chance (hopefully next few days)
Thanks!

[rosenpin]

A quick browsing does not show me function needing refactoring because of complexity. @rosenpin, do you have some in mind ?

As a general rule, as mentioned in the issue description

Separate functions with 3+ indentation levels or over 15 lines

Some example I found include

• get_credentials
• get_callendar_ids
• get_all_events
• get_events_from_cache
• get_string
• get_future_events