added file ending .txt to otu_table and tax_table
added file ending .txt to otu_table and tax_table

iimog/meta-barcoding-dual-indexing,molbiodiv/meta-barcoding-dual-indexing,iimog/meta-barcoding-dual-indexing,molbiodiv/meta-barcoding-dual-indexing,iimog/meta-barcoding-dual-indexing,molbiodiv/meta-barcoding-dual-indexing