Fix bug in to_json_file method
Fix bug in to_json_file method

sorgerlab/indra,bgyori/indra,sorgerlab/belpy,sorgerlab/belpy,bgyori/indra,johnbachman/indra,sorgerlab/indra,johnbachman/belpy,bgyori/indra,johnbachman/indra,johnbachman/belpy,johnbachman/indra,sorgerlab/belpy,sorgerlab/indra,johnbachman/belpy