Release 0.6.1

What's Changed

• bump protox version to match prost version being used. by @GeneralOneill in #70
• Upgrade protobuf-src from 1.1.0 to 2.1.0 by @daniel-b2c2 in #71
• feat: Add customization of type url generation by @asyade in #72
• Add Schemars Support by @jayhf in #77

Full Changelog: v0.6.0...v0.6.1