df2fasta: Conversion of data frames with correct layout to fasta files.
In CMET-UGent/CMETNGS: Convenience functions for CMET NGS automated pipeline

Typically used in conjunction with fasta2dataframe.

df2fasta(
  dataframe,
  filename = "fastadf",
  seqIDcolumn = "SeqIDs",
  seqColumn = "readseq"
)

`dataframe`	a dataframe containing sequence identifiers and sequences in separate columns. with column names
`filename`	desirec filename (defaults to fastadf)
`seqIDcolumn`	string indicating the name of the column with the sequence identifiers (defaults to SeqIDs).
`seqColumn`	string indicating the name of the column with the sequences themselves (defaults to readseq)

## Short example

# Load precomputed example data
data(otureps)
# write out the associated fasta
df2fasta(otureps,filename="oturep.fasta",seqIDcolumn="OTU")