Add support for rand(1..2)

[hyrodium]

This PR fixes #95.

julia> using IntervalSets, Dates

julia> rand(1..2)  # Sampling from uniform distion on 1..2
1.525710842368245

julia> rand(1..2, 3)  # Get three samples
3-element Vector{Float64}:
 1.0470183699383326
 1.406808529012634
 1.2230905556202805

julia> rand(42..42)  # Accepts closed inerval with zero width.
42.0

julia> rand(Interval{:open,:closed}(1,3))  # Only ClosedInterval is supported

ERROR: ArgumentError: Sampler for this object is not defined
Stacktrace:
 [1] Random.Sampler(#unused#::Type{Random.TaskLocalRNG}, sp::Random.SamplerTrivial{Interval{:open, :closed, Int64}, Float64}, #unused#::Val{1})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:146
 [2] Random.Sampler(rng::Random.TaskLocalRNG, x::Random.SamplerTrivial{Interval{:open, :closed, Int64}, Float64}, r::Val{1})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:140
 [3] rand(rng::Random.TaskLocalRNG, X::Random.SamplerTrivial{Interval{:open, :closed, Int64}, Float64}) (repeats 2 times)
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:254
 [4] rand(X::Interval{:open, :closed, Int64})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:259
 [5] top-level scope
   @ REPL[5]:1

julia> rand(42..41)  # Error on empty interval
ERROR: ArgumentError: The interval should be non-empty.
Stacktrace:
 [1] rand(rng::Random.TaskLocalRNG, i::Random.SamplerTrivial{ClosedInterval{Int64}, Float64})
   @ IntervalSets ~/.julia/dev/IntervalSets/src/interval.jl:236
 [2] rand
   @ ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:254 [inlined]
 [3] rand(X::ClosedInterval{Int64})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:259
 [4] top-level scope
   @ REPL[6]:1

julia> rand(Date(2022,04,10)..Date(2022,04,12))  # Only ClosedInterval{<:Real} is supported
ERROR: MethodError: no method matching AbstractFloat(::Type{Date})
Closest candidates are:
  (::Type{T})(::AbstractChar) where T<:Union{AbstractChar, Number} at ~/julia/julia-1.7.1/share/julia/base/char.jl:50
  (::Type{T})(::Base.TwicePrecision) where T<:Number at ~/julia/julia-1.7.1/share/julia/base/twiceprecision.jl:255
  (::Type{T})(::Complex) where T<:Real at ~/julia/julia-1.7.1/share/julia/base/complex.jl:44
  ...
Stacktrace:
 [1] float(x::Type)
   @ Base ./float.jl:269
 [2] gentype(#unused#::Type{ClosedInterval{Date}})
   @ IntervalSets ~/.julia/dev/IntervalSets/src/interval.jl:233
 [3] Random.SamplerTrivial(x::ClosedInterval{Date})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:180
 [4] Random.Sampler(#unused#::Type{Random.TaskLocalRNG}, x::ClosedInterval{Date}, #unused#::Val{1})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:182
 [5] Random.Sampler(rng::Random.TaskLocalRNG, x::ClosedInterval{Date}, r::Val{1})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:140
 [6] rand(rng::Random.TaskLocalRNG, X::ClosedInterval{Date})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:254
 [7] rand(X::ClosedInterval{Date})
   @ Random ~/julia/julia-1.7.1/share/julia/stdlib/v1.7/Random/src/Random.jl:259
 [8] top-level scope
   @ REPL[7]:1

[codecov]

Codecov Report

Merging #104 (d026437) into master (37759b8) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #104      +/-   ##
==========================================
+ Coverage   99.20%   99.22%   +0.02%     
==========================================
  Files           3        3              
  Lines         251      258       +7     
==========================================
+ Hits          249      256       +7     
  Misses          2        2              

Impacted Files	Coverage Δ
src/IntervalSets.jl	99.08% <ø> (ø)
src/interval.jl	99.17% <100.00%> (+0.05%)	⬆️

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[hyrodium]

Without this clamp, the rand may reduce non-unique samples.

julia> a = rand()*10e100
4.4188530133566296e100

julia> unique([rand(a..a) for _ in 1:10000])
3-element Vector{Float64}:
 4.4188530133566296e100
 4.418853013356629e100
 4.41885301335663e100