Agent - 0.9.0

## [0.9.0] - January 8th, 2020
- Capture response time metrics in milliseconds
- Bump to 1.0.0-rc1@d1b332c of the Optimizely go-sdk
- Add metric visibility into event dispatcher
- Miscellaneous clean-up and of docs and openapi spec
- Add top level config package to consolidate configuration
- Incorporate OptimizelyConfig into feature and experiment models
- Add get experiment and list experiment endpoints
- Add user features endpoint for batched decision responses
- Add windows tooling
- Add credit section to README
- Improve service shutdown