You're just not my type #46

# BigFloat inputs silently demote
julia> jd2cal(big"2400000.5", big"50123.999923214120012345").fraction |> typeof
Float64

# Just gives up on Ints
julia> jd2cal(2451545, 0)
ERROR: MethodError: Cannot `convert` an object of type
  StaticArraysCore.SVector{2, Int64} to an object of type
  AbstractVector{<:AbstractFloat}