Update Travis to use Postgres 9.4 for JSONB
Update Travis to use Postgres 9.4 for JSONB

johanneswilm/eha-nutsurv-django,johanneswilm/eha-nutsurv-django,eHealthAfrica/nutsurv,eHealthAfrica/nutsurv,johanneswilm/eha-nutsurv-django,eHealthAfrica/nutsurv