During the recent hash algorithm change it became clear that the choice
of password hash algorithm plays a role in the time taken for CI to run.
Therefore as attempt to improve CI we should consider using a dummy
hashing algorithm instead of a real hashing algorithm.
This PR creates a dummy algorithm which is then set as the default
hashing algorithm during tests that use the fixtures. This hopefully
will cause a reduction in the time it takes for CI to run.
---------
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
