Update default image and fix widget test

Aims to prevent errors like https://gitlab.com/fgimenez/mangrove/-/jobs/1561886289#L35. This new image is maintained https://github.com/Sleavely/docker-node-awscli the previous one didn't have any update for the last 3 years https://hub.docker.com/r/wilson208/circleci-awscli/tags?page=1&ordering=last_updated

Also the widget test is fixed to prevent errors like https://gitlab.com/fgimenez/mangrove/-/jobs/1561906860#L194