Add kapacitor to the ports tree.

Kapacitor is InfluxDB's native data processing engine. It can process both
stream and batch data from InfluxDB. Kapacitor lets you plug in your own custom
logic or user defined functions to process alerts with dynamic thresholds,
match metrics for patterns or compute statistical anomalies.

WWW: https://influxdata.com/time-series-platform/kapacitor/
PR: 210094
Submitted by: Stefan Lambrev