Test scripts for parallel multifit

[tgperring]

In order to test the parallel multifit some CPU-hungry and memory hungry tests for a selection of workspaces are needed. To facilitate creating these, a couple of utility functions have been created that serve to make simple functions take an extraordinarily long time to evaluate while evaluating within a fractional change of less than one part in 10^13. A couple of test scripts have been created in a new test folder test_multifit_parallel to use as templates for making unit tests.

[cmarooney-stfc]

@tgperring Hi Toby - the text here indicates that the various scripts have been created, but there is no link to a PR and I cannot see one in the history. Has this been done? Thanks Chris

[oerc0122]

@tgperring Any more info?