Use a transient file to verify app. default schema

+ The application default schema used for testing is also used for
  migration, unlike the article schema it was modeled after. If this
  optional file is a permanent resident in this gem it must be kept
  up to date with the built in schema.
+ Instead of adding more data to synchronize, create it, inspect it,
  and destroy it during testing.
Merge branch 'feature/app-default-schema'