* Fixed `--plotNumbers` not working in `plotCorrelation`. This was issue #838.
* Fixed compatibility with matplotlib 3 and restrict to at least that version.
* The Y-axis labels should once again appear in both plotHeatmap and plotProfile (issue #844). This was related to the previous point.
* Testing is no longer performed with python 2.7, which will reach end of life in a couple months.
* Various documentation updates (issues #868, #867 and #851).
* Increased support for BED files with track header lines (issue #866).
3.3.0
* `plotCoverage` now has a `--BED` option, to restrict plots and output to apply to a specific set of regions given by a BED or GTF file or files (issue #829).