Tolerate gnocchiclient import errors

currently we are experiencing errors due to `ujson` dependency
of gnocchiclient (see https://github.com/esnme/ultrajson/issues/346).

For now it seems to affect Py2 only, and is fixed in master of that lib,
but until then let's just tolerate failure to load gnocchiclient
and skip that single scenario test where it is used in case of an error.

Change-Id: Ice4f12d875c940c07e22af9170aaa0b258dd5c06
Related-Issue: PRODX-2479
2 files changed