Fix version that supports Python 3.6 on the README
**Documentation**: [https://www.uvicorn.org](https://www.uvicorn.org)
-**Requirements**: Python 3.7+ (For Python 3.6 support, install version 0.15.0.)
+**Requirements**: Python 3.7+ (For Python 3.6 support, install version 0.16.0.)
Uvicorn is a lightning-fast ASGI server implementation, using [uvloop][uvloop] and [httptools][httptools].
