Remove UnitfulIntegration.jl from README

[sostock]

UnitfulIntegration.jl is also no longer needed, QuadGK can handle Unitful quantities since QuadGK v2.1.0.

I decided to remove the entry (instead of declaring it deprecated like UnitfulRecipes.jl) because it cannot even be installed with Unitful 1.x (it requires Unitful 0.x), so it isn’t relevant to the package in its current state.

Closes #376.

[codecov-commenter]

Codecov Report

Merging #578 (577703d) into master (ebad449) will not change coverage.
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[sostock]

I just noticed that infinite integration limits don’t work, so the statement that QuadGK supports Unitful quantities is not correct (infinite integration limits were supported by UnitfulIntegration.jl):

julia> quadgk(x->exp(-x/(1.0m)), 0.0m, Inf*m)
ERROR: DomainError with Inf m:
integrand produced NaN m in the interval (0.0 m, Inf m)
Stacktrace:
[...]

So we should either bring UnitfulIntegration.jl up to date or make a PR to QuadGK to support infinite quantities as integration limits.

[giordano]

That seems to be working now:

julia> using QuadGK, Unitful

julia> quadgk(x->exp(-x/(1.0u"m")), 0.0u"m", Inf*u"m")
(1.0 m, 4.507382674563286e-11 m)