Fix orphaned record bug in parsing_and_importing_spec.

* before(:all) block is importing a file; both transaction and
  truncation based cleanup strategies work around each example, so this
  import is not being cleaned up.
* Move DatabaseCleaner configuration back up into Spork.pre_fork block
  since this is not what's causing the orphaned record.
* Minor refactoring of spec.
Add minimal integration spec with capybara.