Check error codes and raise Julia errors

[isuruf]

This would prevent julia from crashing.

cc @ChrisRackauckas

[ChrisRackauckas]

From SciML/DifferentialEquations.jl#170:

ex = :(x * y - (8 ./ 3.0) * z)
using SymEngine; SymEngine.Basic(ex)

Throwing an error telling the user there's a ./ instead of crashing would be helpful.