Rename fields in the JSON response for more coherence

BREAKING CHANGE: the fields "details" and "ephemerides" have been switched.

feat(ephemerides): compute ephemerides if the position is set only

BREAKING CHANGE: invoking kosmorro command without --latitude and
--longitude arguments will now only output the Moon phase and,
eventually, the events for the given date (or today if date not given).

Add support for opposition events

fix(moonphase): fix the Moon phase prediction

instead of "Planet" in the text format output

Enhance position

BREAKING CHANGE: invoking kosmorro command with the --altitude argument
will now fail with an "unrecognized arguments" error.

Compute more accurate Moon phase

BREAKING CHANGE: JSON format now returns the moon phase as an object
instead of a string

Add codecov

fix(dumper): display the right date on output text

Bump tabulate from 0.8.5 to 0.8.6

Bumps [tabulate](https://github.com/astanin/python-tabulate) from 0.8.5 to 0.8.6.
- [Release notes](https://github.com/astanin/python-tabulate/releases)
- [Changelog](https://github.com/astanin/python-tabulate/blob/master/CHANGELOG)
- [Commits](https://github.com/astanin/python-tabulate/compare/v0.8.5...v0.8.6)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bump skyfield from 1.14 to 1.15

Bumps [skyfield](https://github.com/brandon-rhodes/python-skyfield) from 1.14 to 1.15.
- [Release notes](https://github.com/brandon-rhodes/python-skyfield/releases)
- [Changelog](https://github.com/skyfielders/python-skyfield/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/brandon-rhodes/python-skyfield/compare/1.14...1.15)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

build: add commitlint configuration

fix: set times are now correct