[WIP] OpenAlea integration

[pradal]

Dear all,
I will work on refactoring the package in the point of view of OpenAlea methodology and integration.
Mainly, we provide in OpenAlea/Python:

• Continuous integration on Linux, Mac and Windows
• Build, install and deployment using conda
• Documentation management with ReadTheDoc or githubPages
• ...

I will try to provide soon Pull Request.
On bad thing with OpenAlea is that we rely yet on Python 2.
The other difference is we use SCons (and OpenAlea SConsx) for multi-OS build, install

[DanielLeitner]

We would be very happy to see CRootbox integrated in OpenAlea!

[pradal]

Thanks. I will propose a PR to show case the OpenALea integration. Stay tuned (in september)....