scipy.weave is deprecated

[RafiKueng]

scipy.weave doesn't exist since scipy v0.19 in scipy, but as an external package.

to fix the problem do:

• pip install weave
• replace from scipy import weave by import weave in all files.

[RafiKueng]

/glass.py /glass/basis/pixels/basis.py /glass/basis/pixels/potential.py