tidyplots 0.3.1

Breaking changes

• Removed the parameters widths and heights from split_plot(). Use
  adjust_size() before split_plot() instead.
• Removed the function format_number(), which is available from the scales packages.
• Functions to rename, reorder, sort and reverse the levels of variables mapped to x, y, and color
  now have the suffix _levels() instead of _lables(). For example, rename_x_axis_levels() (#113).

Improvements

• New parameter paired_by in add_test_pvalue() and add_test_asterisks()
  enables paired comparisons.
• New parameter comparisons in add_test_pvalue() and add_test_asterisks()
  enables selected comparisons (#82).
• New parameter my_style in tidyplot() for providing a styling function (#85).
• Support for global tidyplots_options() affecting all tidyplots in the current session.
  Supported options include width, height, unit, dodge_width, and my_style (#84, #85).
• add_annotation_text() now supports colored text (#86).
• Support for axis limits when the axis is of type date, time, or datetime (#97, #99).
• A default jitter seed in add_data_points_jitter(), add_data_labels() and add_data_labels_repel()
  now facilitates the alignment of jittered labels and points (#104).
• Fixed add_histogram() now respects the color parameter (#106).
• New dataset pca containing a principle component analysis.
• New add_ellipse() function (#52).