Timewarrior-balance

Fixed
- When calculating allotted time, the `round_interval` configuration was not
being taken into account and that led to buggy behavior. That has been fixed
now.

BREAKING CHANGES
- Intervals for the report are rounded such that the time for the start date
is set to 0:00:00 and the end timedate is set to next day at 0:00:00. This
provides a less confusing behavior for the user (see
https://github.com/guludo/timewarrior-balance/issues/3). Previous behavior
can be restored by using `round_interval = false` in the configuration file.

Fixed
- Fixed the fix from `0.1.1`: when negative minutes did not amount to at last
one hour, they where formatted as if they where positive, for example: `-41`
would be formatted as `+0:41`. Hopefully we really fixed the issue now.
- Tags described as strings in the configuration would have the first and last
characters because of a bug. That has been fixed.

Fixed
- Fixed bad rounding for negative deltas. Before this fix we would run into
the following situation:

Start: Tue Jan 2 00:00:00 0001
End: Fri Oct 22 08:43:56 2021

Tag Spent Allotted Balance
────────────────────────────────
xyz 103:59 120:00 -17:01

, where the balance should actually be `-16:01`. This is fixed now.

Added
- First release!