Update for influxdb 0.8.6

This is my first time using InfluxDB, so take it with a grain of salt.

I updated the Homebrew formula from the [current version](https://github.com/Homebrew/homebrew/blob/d93de760bd3fbce8c9ca4ea3ae2b26db132d3747/Library/Formula/influxdb.rb), updated the port parameters, and converted the JSON configuration to the current TOML format.