3.20.1: Merge pull request #83 from jasper-eljakim/master

Ignore errors/warnings/notices for the iconv test

3.20.0

Fix compatibility with PHP 7.2.

3.19.0

Updates for version 3.19.

3.18.0

Support fill and fillColour in data label options.

3.17.0

Updates for version 3.17.

3.16.0

Update for SVGGraph 3.16.

3.15.0

Add support for dependency arrows to Gantt charts.

3.14.0

Added gantt_today_date option.

3.13.1

Updates for version 3.13.1.

3.13.0

Update docs for version 3.13.