tune resonance diagram

[oscarxblanco]

Dear all,
I have created on pyat a tune resonance plot equivalent to what is produced by the function reson from @lnadolski on MML.
https://github.com/atcollab/MML/blob/master/mml/reson.m

It follows the color and line style convention from reson, but, this is not a line by line translation of the code. Instead, it partially uses the Farey sequences described here
https://journals.aps.org/prab/abstract/10.1103/PhysRevSTAB.17.014001
R.Tomas. 'From Farey sequences to resonance diagrams' Phys. Rev. ST Accel. Beams 17, 014001 – Published 29 January 2014

Here is an example for resonances of order 1,2, and 5, and for $\nu_x$ between 70 and 70.6, $\nu_y$ between 90 and 90.6, in symmetry 1.

I will share it on a dedicated pull request.
o

[oscarxblanco]

See pull request #809 .