Add JOSS and Zenodo badges to doc

[ahartikainen]

Simple fix.

[aloctavodia]

We may also want to add a short entry like in #544

If you use ArviZ and want to cite it please use

Here is the citation in BibTeX format

@article{arviz_2019,
	title = {{ArviZ} a unified library for exploratory analysis of {Bayesian} models in {Python}},
	author = {Kumar, Ravin and Colin, Carroll and Hartikainen, Ari and Martin, Osvaldo A.},
	journal = {The Journal of Open Source Software},
	year = {2019},
	doi = {10.21105/joss.01143},
	url = {http://joss.theoj.org/papers/10.21105/joss.01143},
}

[ahartikainen]

I added notation about citation. Do you know if there is a way to force newline? Currently I use different blocks between If you use ArviZ and want to cite it .... and Here is .....

[canyon289]

I think | forces newline in rst

[canyon289]

I also have fix for testing failure in my docker PR

[ahartikainen]

I can't get it to work. Feel free to edit this one.

[canyon289]

Ok, wont have time today, might get to it tomorrow or next day

[ahartikainen]

No worries, this can wait :)

[canyon289]

Rebased on top of master

[canyon289]

One or two more days and will get to this

[aloctavodia]

typo: Carroll