qb: update, delete and performance improvements

qb/insert_test.go

@@ -69,6 +69,6 @@ func TestInsertBuilder(t *testing.T) {
 func BenchmarkInsertBuilder(b *testing.B) {
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		Insert("foo").Columns("name", "age", "first", "last").ToCql()
+		Insert("cycling.cyclist_name").Columns("id", "user_uuid", "firstname", "stars")
 	}
 }