Release 0.7.0

[carrascomj]

Improvements

• The plotted data is removed when new data is loaded (instead of stacking it) [DEV] Clean instead of stacking plotting states #33
• The viewport can now be exported to different image formats with the click of a button Feat: save to PNG #36
• The x axes of the histograms are scaled now live (instead of only updating the map for a future render) e386105

TODO

• Fix regression: plotted histograms over axes are no longer rebuilt when the map changes. Probably a matter of scheduling.
• Document new features.
• Bump version.