like below:
````
Configuring gitlab::feature_flags...
- Launching rails runner to set feature flags. This will take some time....
- Specified feature flags to be disabled:
--- "auto_devops_banner_disabled"
--- "invalid_flag_name"
- Specified feature flags to be enabled
--- "git_push_create_all_pipelines"
--- "another_invalid_flag_name"
- Following flags are probably invalid and have been ignored
--- invalid_flag_name
--- another_invalid_flag_name
- Apply user defined feature flags:
--- auto_devops_banner_disabled : off
--- git_push_create_all_pipelines : on
````
- Do not `puts` parsed options (formatted by ruby's `.to_s`),
`puts` each specified target with three hyphens instead
- `puts` each ignored target on each line with three hyphens instead of single line csv
- It requires database is set up because
feature flags are stored to DB (table `application_settings`)
- Add configuration parameter GITLAB_FEATURE_FLAGS_ENABLE_TARGETS
and GITLAB_FEATURE_FLAGS_DISABLE_TARGETS
- Add ruby script to configure feature flags from command line
and invoke runtime (from configure_gitlab())
