Add test for climatic_summary that contains a `summaries_params` parameter about cdms.products

[lloyddewit]

@HawardKetoyoMsatsi Please could you look at this? Thanks
(I don't have rights in this repo to assign people)

[dannyparsons]

Good idea. @HawardKetoyoMsatsi Can you add a test which has the summaries_param argument included?

I think the example Stephen gave is sensible list(mean = list(trim = 0.5)) because trim is a parameter of mean and it will change the result.

Let me know if this makes sense or you have any questions.

[dannyparsons]

(You may need to change the value of trim to get a substantially different output.)