search: PEP8/257 fixes
search: PEP8/257 fixes

Signed-off-by: Leonardo Rossi <5460ec99b71a72e7693c4088b5c2585e76e1c857@cern.ch>

tiborsimko/invenio-search,inveniosoftware/invenio-search,tiborsimko/invenio-search,inveniosoftware/invenio-search