Change source of most of test image samples from docker-hub to local building ones, so it will cost less docker-hub pull requests.
And some of cases like push cnab, they have to use docker-hub, but image samples in cnab test will cost 17 quotas, in this PR, we
replace those samples, now cnab case will cost 6 quotas.
Signed-off-by: danfengliu <danfengl@vmware.com>
1. Since upgrade python to 3.7, some urllib3 warnings come out during
execution, because missing disconnection when using request by docker
library, it's not affect script execution, therefore ignore them first.
2. Replication tests failed in nightly due to new UI code, some element
locators are not valid anymore;
3. Remove switch scanner test steps, since Clair was removed.
Signed-off-by: danfengliu <danfengl@vmware.com>
