Add PostgreSQL 9.4 to test matrix
Add PostgreSQL 9.4 to test matrix

This worked in pg_shard; figured we want it here, too.
olivermel/cstore_fdw,citusdata/cstore_fdw,citusdata/cstore_fdw,olivermel/cstore_fdw,cpcloud/cstore_fdw,cpcloud/cstore_fdw,olivermel/cstore_fdw