Fix doctest_fix for Documenter 1.0

[fingolfin]

No description provided.

[lgoettgens]

LGTM, one comment below you are free to ignore.

[lgoettgens]

Suggested change

	if isdefined(Main.Documenter, :DocTests)
	doctest = Main.Documenter.DocTests.doctest
	else
	doctest = Main.Documenter._doctest
	end
	if isdefined(Main.Documenter, :_doctest)
	doctest = Main.Documenter._doctest
	else
	doctest = Main.Documenter.DocTests.doctest
	end

I would be more inclined to switch up the order, such that the Documenter 1.0 version is the first one. This makes the future dropping of 0.27 support clearer and more readable.

[fingolfin]

I don't agree that it is clearer, one still has to know which version is what. If we want this to be "clear" we need to switch this and other existing checks to check for a version. But that seems to be investing 5 minutes of work now to save 5 minutes of work later, so IMHO not worth it :-)

[lgoettgens]

True :)

[codecov]

Codecov Report

Merging #2852 (7b909e0) into master (1a11d14) will decrease coverage by 0.02%.
Report is 1 commits behind head on master.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #2852      +/-   ##
==========================================
- Coverage   80.67%   80.65%   -0.02%     
==========================================
  Files         456      456              
  Lines       64717    64720       +3     
==========================================
- Hits        52208    52203       -5     
- Misses      12509    12517       +8     

Files Changed	Coverage
src/utils/docs.jl	0.00%