communities: enabling search by id
communities: enabling search by id

* Allows search by id. (closes zenodo/zenodo#91)

* PEP8 Fixes.

Signed-off-by: Adrian Pawel Baran <3f0d95b8f073876984c6beaffa367600a8350ef3@cern.ch>
Reviewed-by: Jiri Kuncar <2bdffcb416fed3002465740d19a053a39918cbe5@cern.ch>

inveniosoftware/invenio,inveniosoftware/invenio,tiborsimko/invenio,tiborsimko/invenio