update dep versions in readme, setup, requirements

[vermeeren]

closes #416

[t-b]

@melvinvermeeren

Using >= instead of == sounds like a good idea.

I think we should depend on sphinx 1.8.4 or later due to the recent bugfixes.

Are you really still using doxygen 1.8.4? This part of the readme and also the part about the xml errors in doxygen 1.5.1 seems more like of historic interest.

[vermeeren]

@t-b

It should also work (even if with bugs) with 1.8.0 though as the API is compatible, so I believe marking this as absolute minimum is better. In practice I do expect people that run the latest breathe to also run the latest sphinx for all the bugfixes.

As for the other deps, they are horribly outdated and breathe or sphinx might not even work with the versions mentioned. Doxygen 1.8.4 appears to be from 2013, Debian jessie (oldstable) has 1.8.8. We don't have any proper tests or CI with various python environments to properly validate minimum versions so I'm not sure what this should be changed too. Probably leave it as is until we get some bug report or proper validation going?

[t-b]

It should also work (even if with bugs) with 1.8.0 though as the API is compatible, so I believe marking this as absolute minimum is better. In practice I do expect people that run the latest breathe to also run the latest sphinx for all the bugfixes.

Okay, if this was taken into consideration, this sounds good as well.

Probably leave it as is until we get some bug report or proper validation going?

Yes let's leave it for now.