Use --allow-insecure-ssl instead of -i

Signed-off-by: Jason Bernardino Alonso <jalonso@luminoso.com>
Use 'insecure_registry' as a keyword argument consistently

Signed-off-by: Jason Bernardino Alonso <jalonso@luminoso.com>
Merge pull request #1 from LuminosoInsight/insecure-pull-cleanup

Insecure pull cleanup