Update insta requirement from 0.15 to 0.16
Update insta requirement from 0.15 to 0.16

Updates the requirements on [insta](https://github.com/mitsuhiko/insta) to permit the latest version.
- [Release notes](https://github.com/mitsuhiko/insta/releases)
- [Changelog](https://github.com/mitsuhiko/insta/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mitsuhiko/insta/compare/0.15.0...0.16.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
brendanzab/codespan