ERROR: LoadError: - not defined for DoubleDouble.Single{Float64}

[GlenHertz]

I'm trying to use this library but I get the following:

julia> Single(1.0) - Single(0.0)
ERROR: - not defined for DoubleDouble.Single{Float64}
Stacktrace:
 [1] -(::DoubleDouble.Single{Float64}, ::DoubleDouble.Single{Float64}) at ./promotion.jl:337