CSV input file type not supported in practice

[phillip-stephens]

The --help says that csv input files are supported when they are not in practice.

⋊> ~/zannotate on master ◦ ./zannotate --help                                                                                                                                                                                                                                                                                                 14:26:43
Usage of flags:
...
  -input-file-type string
        ips, csv, json (default "ips")
...
⋊> ~/zannotate on master ◦ ./zannotate --input-file-type csv                                                                                                                                                                                                                                                                                  14:26:47
FATA[0000] invalid input file type  

Reproducibility

This was seen in master branch. ( b1f259a)