Pass format to CLI#parse.

Author: gkellogg

lib/rdf/cli.rb

@@ -450,6 +450,7 @@ def self.parse(files, evaluate: nil, format: :ntriples, encoding: Encoding::UTF_
           yield(reader)
         end
       else
+        options[:format] = format if format
         files.each do |file|
           RDF::Reader.open(file, options) do |reader|
             (@readers ||= []) << reader.class.to_s