Improve the installation steps of AMC and Tahoe's Open edX

[OmarIthawi]

We won't probably get to this at the moment for Ficus. But I think the same feedback would work for the ongoing Hawthorn efforts:

• Move the manual AMC installations, into Ansible
• Refactor the circular dependency between AMC and Open edX Tahoe
• tiers didn't work for me, because, edx-organization weren't in sync between both databases as edx-orgnization is missing a field:

  ProgrammingError at /admin/tiers/tier/
  column organizations_organization.short_name does not exist
  LINE 1: ...."modified", "organizations_organization"."name", "organizat...
                                                          ^
  

• Tests didn't work. AMC is heavily customized, the configuration helpers has a hefty hacks that we probably need to refactor for the tests to work.

[OmarIthawi]

fyi: @johnbaldwin please feel free to add to the list.

[OmarIthawi]

This is not resolved by using the Docker devstack.