Release 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