Simplify bok choy environments to inherit pipeline settings from common.py
Merge pull request #4597 from edx/benp/fix-bok-choy-solano

Simplify bok choy environments to inherit pipeline settings from common.
Fix false positive test in cms acceptance

This test was passing in Jenkins, but failing in our Solano runs (and locally on firefox).
This is because it was attaching a file that was not there. This change fixes the test
and makes the attachment method smarter so it will fail if it tries attaching a non-existent
file.
Add test file used for format validation.
Merge pull request #4591 from edx/benp/fix-attach-file

Fix false positive test in cms acceptance, harden attach_file helper.
Refactor ADVANCED_COMPONENT_TYPES

    Modified to a setting in CMS common.py and aws.py
    Also factored out are: ADVANCED_PROBLEM_TYPES

    This enables third parties to add XBlocks to their system
    without having to make a code change.

    Code also added to ensure that a component should exist in both
    ADVANCED_COMPONENT_TYPES and the course advanced module list
    in order for it to be enabled in the course.