TiagoOlivoto/metan: 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