Agent - 0.8.0

## [0.8.0] - November 18th, 2019
- Adds ability to limit the number of active api connections
- Allows SDK keys to be bootstrapped during startup
- Adds http server timeouts
- Adds graceful shutdown hooks
- Adds support for forced variation API
- Adds support for experimentation APIs

https://github.com/optimizely/agent/releases/tag/v0.8.0