Return non zero exit code if LAMMPS errors out in the raw calculation

[JPchico]

I noticed that in the LammpsRawCalculation the calculation can end up with a zero exit code even if LAMMPS exited with an error. I think that one should add a simple check like the one in the LammpsBaseCalculation where one checks if an error was printed to the stdout and then exit with a non-zero exit code. https://github.com/aiidaplugins/aiida-lammps/blob/77f4594bb21dc5c4c99c13a7884e28c6356d1f04/aiida_lammps/parsers/base.py#L72-L77

[JPchico]

@sphuber this is also something that I'll add after #77 is done.

[JPchico]

Closed via #90