Ansible: Fix installing MongoDB
Ansible: Fix installing MongoDB

Update the public key used to authenticate the MongoDB packages to the
key used to sign the 3.6 release. This fixes the following error during
the "mongodb : Install package" task during Ansible provisioning:

    There were unauthenticated packages and -y was used without --allow-unauthenticated

ImageMarkup/isic-archive,ImageMarkup/isic-archive,ImageMarkup/isic-archive,ImageMarkup/isic-archive