Scikit-plot

New features:
* `plot_precision_recall_curve` and `plot_ks_statistic` now have a new `curves` argument that allows the user to choose which curves should be plotted. Thanks to doug-friedman for this PR.
* Jupyter notebook examples are now available thanks to lstmemery

New features:
- plot_pca_2d_projection function
- plot_pca_component_variance function
- plots now have a `figsize`, `title_fontsize`, and `text_fontsize` feature to allow user to customize the size of the plot. This is particularly crucial for Jupyter notebook users where the default settings come out too small. Thanks to frankherfert for this idea.

Minor changes to examples repo.

Release to trigger Zenodo webhook.

Added Functions API

Welcome to the first ever release of scikit-plot. Hope you find this small library useful!