Fix precision mixing in RodasTableau and better test precision mix

Fixes #2524

Author: ChrisRackauckas

lib/OrdinaryDiffEqRosenbrock/src/rosenbrock_tableaus.jl

@@ -225,7 +225,7 @@ end
 struct RodasTableau{T, T2}
     A::Matrix{T}
     C::Matrix{T}
-    gamma::T
+    gamma::T2
     c::Vector{T2}
     d::Vector{T}
     H::Matrix{T}

test/interface/precision_mixing.jl

@@ -85,6 +85,7 @@ end
     if !is_APPVEYOR && (GROUP == "All" || GROUP == "InterfaceIV" || GROUP == "Interface")
         @time @safetestset "Autodiff Error Tests" include("interface/autodiff_error_tests.jl")
         @time @safetestset "Ambiguity Tests" include("interface/ambiguity_tests.jl")
+        @time @safetestset "Precision Mixing Tests" include("interface/precision_mixing.jl")
         @time @safetestset "Sized Matrix Tests" include("interface/sized_matrix_tests.jl")
         @time @safetestset "Second Order with First Order Solver Tests" include("interface/second_order_with_first_order_solvers.jl")
     end