Add newer versions for 51 Python packages (#10738)

var/spack/repos/builtin/packages/py-alabaster/package.py

var/spack/repos/builtin/packages/py-astroid/package.py

var/spack/repos/builtin/packages/py-babel/package.py

var/spack/repos/builtin/packages/py-basemap/package.py

var/spack/repos/builtin/packages/py-cffi/package.py

var/spack/repos/builtin/packages/py-cython/package.py

var/spack/repos/builtin/packages/py-dask/package.py

var/spack/repos/builtin/packages/py-docutils/package.py

var/spack/repos/builtin/packages/py-flake8/package.py

var/spack/repos/builtin/packages/py-h5py/package.py

var/spack/repos/builtin/packages/py-hypothesis/package.py

var/spack/repos/builtin/packages/py-imagesize/package.py

...ack/repos/builtin/packages/py-ipython-genutils/package.py

var/spack/repos/builtin/packages/py-ipython/package.py

var/spack/repos/builtin/packages/py-jinja2/package.py

...k/repos/builtin/packages/py-keras-applications/package.py

.../repos/builtin/packages/py-keras-preprocessing/package.py

var/spack/repos/builtin/packages/py-lit/package.py

var/spack/repos/builtin/packages/py-matplotlib/package.py

var/spack/repos/builtin/packages/py-mpi4py/package.py