Epic Task Support Foundation

[metaskills]

I found a few key bugs while working to support two critical tasks, migrate :up and :down. Please read over the commits for details. I'll be stacking a few more commits on top of this. I think the biggest thing I learned is as follows:

• The SecondBase.on_base was not nested happy and needed a bit of state tracking.
• Most ah-hoc SecondBase only tasks require that we call db:load_config beforehand so on base state wins.

A few key changes also include:

• The dummy_migration helper makes a real secondbase migration. Helper returns both the version and file which different tests/helpers utilize.
• Removed redundant run helpers. Now only run_db and run_secondbase are needed. These take a rake task argument and an optional stream to capture. This is critical as some tasks use :stdout for errors before Rails 4.2 fixed them to go to :stderr. The test DSL is now better for it too.
• Did some meta programming for the Rails version helpers. Now includes exact and exact & up query methods.

[metaskills]

cc @hmadison

[hmadison]

Looks good to me.