Rational requires <: Integer. See https://github.com/JuliaLang/julia/blob/f38c537ec6a02e18fb4934b4ee9fe2c26f03bf36/base/rational.jl#L3. We need to implement a TracedRational and convert Rational types to TracedRational in a separate file similar to TracedRange types. We need to implement the functions in that file for our new type