Remove inaccurate reference to 'folded'
Basic integration test for munging process

Please add to these test as appropriate to capture edge cases for the
munging process.

There's a known issue with capitalisation this test captures, which
we'll fix at a later date and remove the warning. See this ticket[1]
for a description of the bug.

[1] https://www.pivotaltracker.com/story/show/44805633
Integration test for folding mappings
Split fold-mappings from main munge process

We still call into the legacy `MappingFetcher` class, but we've
non-language specific tests wrapping the new script so we're free to
re-implement as we see fit.