Ensure the Bio.SeqIO.GckIO module can be tested even in offline
mode by reading an in-tree artificial sample file.
This sample file has been handcrafted based on what I know about
the Gck format, solely for the purpose of testing the parser. It
is not even sure the original Gene Construction Kit program would
accept that file without barking.
Testing the parser against real files is still recommended. The
test module will still do that automatically using files from the
Drosophila Gateway Vector Collection provided those files can be
downloaded.
The directory must exist before we can attempt to write anything
into it. It's better to ensure that at the repository level than
doint it in the test setup phase.
