add some python packages in python3_scientific (from pypi)

[thefab]

• basemap
• cdsapi
• Fiona
• pandas
• pygraphviz
• graphviz
• scikit-learn

[thebaptiste]

There is a difficulty with basemap. This package has non entry in https://pypi.org/simple/basemap/ because it is too big (about 130 Mo, see here.
So pip install basemap doesn't work, we must install it specifying directly the tar.gz url in requirements3.txt : https://downloads.sourceforge.net/project/matplotlib/matplotlib-toolkits/basemap-1.0.7/basemap-1.0.7.tar.gz#egg=basemap
I had to add downloads.sourceforge.net in trusted-host for pip install to work behind our proxy at Meteo-France.
See PR adding the possibility to pip install a package from https url outside pypi.org

[thebaptiste]

Done (for python3_scientific and python2_scientific) for :

• basemap
• cdsapi
• pandas
• graphviz
• scikit-learn

Not done for :

• Fiona : doesn't build on CentOS6 with gcc 4.4.7 (have to try with scl)
• pygraphviz : needs graphviz and graphviz-devel rpms to build, we will build graphviz in scientific layer

[thebaptiste]

Done for pygraphviz
Still missing Fiona

[thebaptiste]

Done for Fiona