Plot using Python variables

[marctorsoc]

I think it'd be nice and not really complicated to add support to plot from two variables in lists/np.array's. This would be useful when e.g. debugging in a command-line in a remote server.

I can contribute if no one else volunteers to do it and the authors agree on adding this

[liwt31]

I believe it is currently supported in the master branch. The pypi version is too old indeed.