build: ignore metacheck warnings for go 1.8
build: ignore metacheck warnings for go 1.8

Ignores errors like:

cli/sql_util.go:41:2: driver.Execer is deprecated: Drivers should implement ExecerContext instead (or additionally).  (SA1019)

paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach