Who was the trainer with Robert Courtney was owner?
CREATE TABLE "winners_of_the_colonial_turf_cup" (
  "year" real,
  "winner" text,
  "jockey" text,
  "trainer" text,
  "owner" text,
  "distance_miles" text,
  "time" text
);
SELECT "trainer" FROM "winners_of_the_colonial_turf_cup" WHERE "owner"='robert courtney';