Inline-snapshot

Fix

- changed how --inline-snapshot=disable works in combination with xdist (90)
- fix typo, rename 'theme' with 'them'

Fix

- trigger no update for trailing comma changes

BREAKING CHANGE

- removed support for python 3.7
- removed `--inline-snapshot-disable` option and replaced it with `--inline-snapshot=disable`

Feat

- new flags: *disable*, *short-report*, *report* and *review*
- added config option and environment variable to specify default flags
- show diff of changed snapshots in pytest report
- interactive *review* mode

Feat

- check if inline-snapshot is used in combination with xdist and notify the user that this is not possible

Fix

- change the quoting of strings does not trigger an update

Fix

- removed restriction that the snapshot functions has to be called snapshot (72)
- report error in tear down for sub-snapshots with missing values (70)
- element access in sub-snapshots does not create new values

Fix

- make typing less strict