Fix continuous colour chart

[edwardchalstrey1]

Closes #63

• Make sure y axis of colour plot lines up with histogram plot for imdb scatter example opened new issue Colours used: scatterplot example goes beyond data range #82
• Update test for continuous scale plot TestMetaHist.test_scatterplot_bin_False
• Update all tests due to change in title and y axis labelling on colours used/ density plots
• Merge develop into this branch
• Refactor

[edwardchalstrey1]

@rolyp I think it might be impossible to plot the continuous scale properly on the colours used plot - this solution is almost there but doesn't look quite right, I think if I can't find a solution today though it may be worth just merging anyway to focus on finishing the notebooks and opening a new issue like "make continuous colour scale look fully continuous"

[rolyp]

Ok, I'll take a look now.

@rolyp I think it might be impossible to plot the continuous scale properly on the colours used plot - this solution is almost there but doesn't look quite right, I think if I can't find a solution today though it may be worth just merging anyway to focus on finishing the notebooks and opening a new issue like "make continuous colour scale look fully continuous"

[edwardchalstrey1]

Ok, I'll take a look now.

@rolyp I think it might be impossible to plot the continuous scale properly on the colours used plot - this solution is almost there but doesn't look quite right, I think if I can't find a solution today though it may be worth just merging anyway to focus on finishing the notebooks and opening a new issue like "make continuous colour scale look fully continuous"

@rolyp this seems to be almost there, the y ticks on the "colours used" chart seem to not exactly line up for the continuous scatter plot, must be some small tweak I can make here that I'm yet to figure out

[rolyp]

@edwardchalstrey1 Replied on Slack but probably better to put it here.) Yes, I see what you mean re. the ticks not lining up 😞 I vaguely recall that being a problem we "solved" by setting nice=True! Let's experiment a bit more -- the ticks lining up is I guess a non-optional feature, but it does seem annoying that we can't force that (other than by reverting the nice setting).