Added test data
Commiting first draft of `test.hs`

This contains the code to do the MD5 digest of the contents of a directory
Factored the search out into a `Producer`

This is so that the test suite can reuse it without having to shell out to call
the executable
Renamed 'suns-cmd.hs' to 'Main.hs'

This is to that the test suite can import code from that module
Completed first draft of test suite