Fix the data_generation plot of whitened data

The plotting utility in bilby_pipe had some of the same errors in producing whitened strain that are addressed in this bilby MR. Here I am fixing this plotting function to plot unit-variance strain in both the time and frequency domains.

After bilby!1205 (merged) is merged will this fix stay the same?

Yes, that MR is a dependency of this one. The fix here is contingent on those changes being merged first.

@sylvia.biscoveanu, with the new release are we ready to get this merged in? Could you rebase to master?

Sorry, I reviewed it locally and merged (in effect approving the MR and merging).

merged

changed milestone to %1.3.0