databases/timescaledb: Update from 0.2.0 to 0.3.0

[joneum]

Summary

• databases/timescaledb: Update from 0.2.0 to 0.3.0
• pet portlint
• Changelog: https://github.com/timescale/timescaledb/blob/master/CHANGELOG.md

PR: 221371
Submitted by: kbowling (maintainer)
Approved by: xxx (mentor)
#Differential Revision: https://reviews.freebsd.org/Dxxxxx

Test Plan

~/dev/ports/databases/timescaledb % portlint -AC
WARN: Makefile: for new port, make $FreeBSD$ tag in comment section empty, to make SVN happy.
0 fatal errors and 1 warning found.

poudriere testport:

10.3-amd64
10.3-i386
11.1-amd64
11.1-i386
12.0-CURRENT r321899 amd64
12.0-CURRENT r321913 i386