Distutils fails with numpy 1.19

[dylanmikesell]

I noticed that the tomo plugin fails with the newest numpy (1.19). This has already been noticed in Obspy (issue 2643). I plan to fix this after I submit a different pull request to address some FTAN.py issues. Will try to get to it later today.

Example of the current error thrown is below. Current work around is to use numpy 1.18.1.

python setup.py install

Traceback (most recent call last):
  File "setup.py", line 19, in <module>
    from numpy.distutils.core import DistutilsSetupError, setup
ImportError: cannot import name 'DistutilsSetupError' from 'numpy.distutils.core' (/Users/dmikesell/anaconda3/envs/tomo/lib/python3.7/site-packages/numpy/distutils/core.py)

[megies]

see obspy/obspy#2643 for the fix @ThomasLecocq

[ThomasLecocq]

oki, will do ! thanks !

[dylanmikesell]

Fixed with 51a8292.