v2.8.0

Changelog

• receiver-mock: remove duplicated short flags for logs and metrics by @pmalek-sumo in #194
• feat(receiver-mock): add collector registration and heartbeat handlers by @pmalek-sumo in #192
• feat(receiver-mock): get metadata from X-Sumo-* headers by @swiatekm-sumo in #193

Full Changelog: v2.7.0...v2.8.0