metan 1.12.0

New functions

• get_levels_comb() to get the combination of the levels of a factor.
• g_simula() to simulate replicated genotype data.
• add_row_id() to add a column as the row id.
• remove_rownames(), column_to_rownames() and rownames_to_column() to deal
  with rownames.

Minor improvements

• New argument sel.var() in corr_ci() to filter correlations with a selected
  variable
• New arguments fill and position.fill in plot_ci() to fill correlations
  by levels of a factor variable.
• Remove deprecated arguments in arrange_ggplot() and gge().
• New argument theme in arrange_ggplot() to control the theme of the plot.
• Include by argument in gafem().
• mgid() now understands models of class gafem_grouped.
• Fix bug in get_levels() to get the levels even if the variable is not a factor.