Fixed Issue 30 by asmeurer.
Fixed Issue 30 by asmeurer.

github4ry/sympy_gamma,kaichogami/sympy_gamma,debugger22/sympy_gamma,github4ry/sympy_gamma,kaichogami/sympy_gamma,iScienceLuvr/sympy_gamma,bolshoibooze/sympy_gamma,bolshoibooze/sympy_gamma,bolshoibooze/sympy_gamma,iScienceLuvr/sympy_gamma,iScienceLuvr/sympy_gamma,debugger22/sympy_gamma,kaichogami/sympy_gamma,github4ry/sympy_gamma