fix namespace to taxa::taxon_names function

NAMESPACE

@@ -81,7 +81,6 @@ importFrom(metacoder,compare_groups)
 importFrom(metacoder,diverging_palette)
 importFrom(metacoder,heat_tree)
 importFrom(metacoder,parse_phyloseq)
-importFrom(metacoder,taxon_names)
 importFrom(metacoder,zero_low_counts)
 importFrom(microbiome,aggregate_top_taxa)
 importFrom(microbiome,core_members)
@@ -95,4 +94,5 @@ importFrom(plotly,ggplotly)
 importFrom(ranacapa,ggrare)
 importFrom(reshape2,melt)
 importFrom(taxa,filter_obs)
+importFrom(taxa,taxon_names)
 importFrom(venn,venn)