findBin search in PATH env with searchInPath flag

Search in PATH env only if bin haven't been found in sdk dirs.

Change-Id: If09873138b2855e0fc6cb0efaaaea8788d211992
Reviewed-on: http://gerrit.aldebaran.lan/45964
Tested-by: gerrit
Reviewed-by: ncornu <ncornu@aldebaran-robotics.com>