[tests] build a local gantry image to run container tests. Also used … #830

Job	Run time
shellcheck	13s
Run container tests	3m 19s
Test script (gantry_cleanup_images_spec.sh)	56s
Test script (gantry_common_options_spec.sh)	1m 6s
Test script (gantry_filters_spec.sh)	1m 4s
Test script (gantry_jobs_spec.sh)	41s
Test script (gantry_login_docker_config_spec.sh)	1m 2s
Test script (gantry_login_negative_spec.sh)	58s
Test script (gantry_login_spec.sh)	1m 0s
Test script (gantry_manifest_spec.sh)	1m 1s
Test script (gantry_notify_spec.sh)	1m 14s
Test script (gantry_parallel_spec.sh)	59s
Test script (gantry_rollback_spec.sh)	50s
Test script (gantry_service_multiple_spec.sh)	32s
Test script (gantry_service_no_running_tasks_spec.sh)	54s
Test script (gantry_service_single_spec.sh)	54s
Test script (gantry_update_options_spec.sh)	52s
Build and push Docker image	58s
	18m 33s

Provide feedback