[epic] Improve plotting

[mastoffel]

plot_results() currently produces a simple scatterplot the best fold for each model and each fold for a single model

To do:

• Make plotting flexible in shape #130
  • depending on how many plots to plot (a 3 x 4 panel looks better than a 1 x 12 panel). Should also take an argument to specify this.
• Make plot_results() work for multi-output #131
  • (2d y). This will result in many plots so needs a strategy for staying readable, such as taking a subset or pages.
• Add tests for plotting #132
• Add plot with variance around points for GP's and models that have a return_std() argument #133

[kallewesterling]

@mastoffel This issue needs splitting up into pieces that can take us towards the plotting being done as part of the MVP, if that's important for our next three sprints. I'm happy to take a first stab at it, if you'd like.

[mastoffel]

@mastoffel This issue needs splitting up into pieces that can take us towards the plotting being done as part of the MVP, if that's important for our next three sprints. I'm happy to take a first stab at it, if you'd like.

@kallewesterling That would be great. Have changed it slightly and added a task.

[kallewesterling]

Thanks @mastoffel! I have separated them out as issues related to this epic now.