- Remove Python 3.6 support
- Convert to default ANSI escape code colored diff output in terminal environments only (this is a change in behavior from previous default that required `-c` / `--color` option to toggle colored output on)
- Add new `--nocolor` option to disable colored diff output in terminals
- Maintain `-c` / `--color` option to toggle ANSI escape code colored diff output on in non-terminal environments and avoid breakage in existing workflows
- Modify user notice on no OpenTable diff from "There is no difference between the files" to "There is no difference in the tested OpenType tables"
- Stabilize external executable diffs with the `--external` option
- Add Python 3.10 testing, drop Python 3.6 testing
- Bump aiofiles dependency to v0.7.0
- Bump cffi dependency to v1.15.0
- Bump fonttools dependency to v4.27.1
- Bump idna dependency to v3.3
- Bump multidict dependency to v5.2.0
- Bump pycares dependency to v4.1.2
- Bump pygments dependency to v2.10.0
- Bump rich dependency to 10.12.0
- Bump typing-extensions dependency to v3.10.0.2
- Bump yarl dependency to v1.7.0