Bump letter_opener from 1.6.0 to 1.7.0
Bump letter_opener from 1.6.0 to 1.7.0

Bumps [letter_opener](https://github.com/ryanb/letter_opener) from 1.6.0 to 1.7.0.
- [Release notes](https://github.com/ryanb/letter_opener/releases)
- [Changelog](https://github.com/ryanb/letter_opener/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ryanb/letter_opener/compare/v1.6.0...v1.7.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
cesy/growstuff,cesy/growstuff,Growstuff/growstuff,Growstuff/growstuff,yez/growstuff,cesy/growstuff,Growstuff/growstuff,yez/growstuff,Br3nda/growstuff,Br3nda/growstuff,Br3nda/growstuff,cesy/growstuff,yez/growstuff,Br3nda/growstuff,yez/growstuff,Growstuff/growstuff