doctest failure on v1.7

[vtjnash]

One of the doctests has started failing on nightly (https://s3.amazonaws.com/julialang-reports/nanosoldier/pkgeval/by_date/2021-06/03/JuMP.1.7.0-DEV-9f32653992.log) due to a change in the sort order of Dict affecting the order in which the object is printed.

I've learned recently of this work to make doctests automatically updated by CI:
beacon-biosignals/KeywordSearch.jl#18

(along with their recommendation to run them only on one specific version of Julia, so that you aren't chasing continual minor formatting changes)