Create Vignette for using base plot tester

[lwasser]

let's create a vignette for base plot tester. Following earthpy for an example of creating a vignette. https://github.com/earthlab/earthpy/blob/master/examples/plot_bands_functionality.py

it will become an example in the gallery like this: https://earthpy.readthedocs.io/en/latest/gallery_vignettes/index.html

In this vignette:

1. create a basic scatter plot
2. create a plot tester object for it.
3. test that:
   • the title contains a word,
   • that there is an x and y axis label
   • that the plot is of type scatter plot
   • test that the data are correct in the plot

i believe i'll have to setup the gallery functionality in matplotcheck like it's setup in earthpy

https://github.com/earthlab/matplotcheck/blob/master/docs/conf.py#L43 https://github.com/earthlab/earthpy/blob/master/docs/conf.py#L48

for this to work properly and build locally.

[lwasser]

@lwasser needs to get a good assignment from @jlpalomino !! jenny do you have a homework assignment that we can use as a use case for matplotcheck?! i'll ping you on slack as well.