Force colors in CI

Author: pquentin

.buildkite/run-repository.sh

@@ -43,6 +43,7 @@ docker run \
   --env "TEST_SUITE=${TEST_SUITE}" \
   --env "PYTHON_CONNECTION_CLASS=${PYTHON_CONNECTION_CLASS}" \
   --env "TEST_TYPE=server" \
+  --env "FORCE_COLOR=1" \
   --name elasticsearch-py \
   --rm \
   elastic/elasticsearch-py \