see 0.11.0

Changes

• All theme_*() function get a ... argument that is passed to
  ggplot2::theme().

• Arguments that change the size of elements in theme_*() functions (like
  plot.title.size or axis.text.size now scale with the base_size argument,
  to ensure proper scaling of plots when the base-size is changed.

• Added a new theme, theme_azurelight(), with a light-blue character, and
  reduced use of grid lines.

• theme_modern() now recognizes a show.ticks argument, to add tick marks
  to the plot and slightly increase the distance between axis labels and the
  related axis.

• Color scale functions (those starting with scale_*()) get a new "gradient"
  palette, which are simply the color values for blue and orange colors from that
  palette. Furthermore, color scale functions now automatically select an
  appropriate palette (usually, "contrast" or "gradient") depending on
  whether discrete or continuous color scales are requested.

Bug fixes

• Fixed issue with adding prior layers to plots from estimate_density().