Updating the Ecto test database

I had a problem where the test database wasn't updating correctly. It usually does this automatically from the migrations. [Posted problem + answer here](http://stackoverflow.com/questions/42162347/how-to-rollback-reset-or-drop-ecto-test-database/42162348#42162348) 👍 .

Start by locating the Ecto migration and test-database guidance, then compare it with the linked Stack Overflow problem and answer. Done means the project clearly explains how to recover when the test database does not update automatically, including the relevant rollback, reset, or drop steps.

Written by the indexing model from the issue text.