NAME
Catmandu::Importer::DOI - Package that imports DOI data.
Take an existing DOI and lookup the metadata for it.
SYNOPSIS
  use Catmandu::Importer::DOI;
  my %attrs = (
    doi => '<doi>',
    usr => '<your-crossref-username>',
	pwd => '<your-crossref-password>',
	format => '<xsd_xml | unixref | unixsd | info>'
  );
  my $importer = Catmandu::Importer::DOI->new(%attrs);
  my $n = $importer->each(sub {
    my $hashref = $_[0];
    # ...
  });