WIP: Use Numpy modules directly instead of SciPy aliases

[StellarStorm]

Commit 1: switch scipy.random to np.random
See scipy/scipy#14889 for reference

In current SciPy versions, scipy.random is no longer a thing (was previously an alias for np.random)

[loli]

Working on a same files ATM - never thought I would see a PR clash on this repo :)

If you feel like picking up a task, these are definitely on the todo list:

• Review and update badges in README.md
• Bioconda
  • Now in conda-forge: https://anaconda.org/conda-forge/medpy
  • test install and update docu (e.g. https://loli.github.io/medpy/installation/conda.html) accordingly
  • edit recipes to point to 0.5.0:
    • maybe this: https://github.com/conda-forge/medpy-feedstock ?
    • seem like it, version is here: https://github.com/conda-forge/medpy-feedstock/blob/main/recipe/meta.yaml
• Remove travis build
  • move to github builds, if possible

[loli]

Closed, as already changed. Todo list in #122