If fortpy was compiled with a different version of gfortran we should catch it and recompile rather than failing.

[wsmorgan]

factorial_int_rank1.f90:6:6:

   use fortpy
      1
Fatal Error: Cannot read module file 'fortpy.mod' opened at (1), because it was created by a different version of GNU Fortran
compilation terminated.
gfortran: error: factorial_int_rank1.o: No such file or directory