Upgrade to Go 1.17, protobuf v1.26.0, etc

What's Changed

• add stitch proto by @mhamrah in #1
• Upgrade to Go 1.17, protobuf v1.26.0 by @jcburley in #2

New Contributors

• @mhamrah made their first contribution in #1
• @jcburley made their first contribution in #2

Full Changelog: https://github.com/namely/giraffe-proto/commits/v0.1.0