Build #193 of python-control/Slycot did not pass for OSX yet

[kangwonlee]

• As of https://github.com/python-control/Slycot/commit/b89132c0abb4e7a1a77b10178fa2bd9783b40d41

python version	link to the error message
3.5	https://travis-ci.org/python-control/Slycot/jobs/554946094#L2381
3.6	https://travis-ci.org/python-control/Slycot/jobs/554946095#L2403
3.7	https://travis-ci.org/python-control/Slycot/jobs/554946096#L2407

• Seems slycot/_wrapper.cpython-{35m, 36m, 37m}-darwin.so could not find some image file
• Need to check conda forge?
• Could find an advice regarding numpy
• Are the numpys of conda for OSX not normal?