weird 3.0.0

• Moved the Old Faithful Geyser examples from the README into a new vignette, vignette("old-faithful").
• augment() method added for rrcov Pca* objects, returning the principal component scores, score distances and orthogonal distances, optionally alongside the original data.
• dist_mclust() added to convert a Gaussian mixture model (Mclust object) to a distributional object.
• density_df() added, converting a distributional object to a data frame containing density values over a grid, suitable for plotting.
• biplot_projection() added, drawing a two-dimensional projection of scores with the original variable axes overlaid as arrows.
• outlier_map() added, drawing the score distance against the orthogonal distance for a prcomp or rrcov Pca* object, with optional cutoff thresholds classifying observations as regular, good leverage points, orthogonal outliers or bad leverage points.
• Added fetch_air_quality() to download Beijing air quality data from 12 monitoring stations (2013-2017).
• Added gun_deaths dataset containing firearm homicide rates and gun ownership by country for 2017.
• wine_reviews columns have been reordered.
• gg_density_layer() removed,
• lof_scores() now returns 1 (instead of 0) when there are too many duplicates.
• mvscale() now better handles missing and infinite values, and returns centering and scaling terms as attributes.
• dist_kde() is now robust to missing values.
• Removed several dependencies
• Bug fixes and documentation improvements