test-sdf-expand-grid should require Spark 2 or above (#2793)
test-sdf-expand-grid should require Spark 2 or above (#2793)

Signed-off-by: Yitao Li <506e136862ca6a2cd6209c2ab7376874a235e7c2@rstudio.com>
rstudio/sparklyr,rstudio/sparklyr,rstudio/sparklyr,rstudio/sparklyr