Conda recipe

I've created a conda recipe for TIGRE. Actually 2 ways of doing it:

* https://github.com/paskino/TIGRE/tree/conda_recipe integrates the recipe in this repo
* https://github.com/paskino/TIGRE-conda will download the TIGRE source from github and patch it to compile

IMHO, it'd be better to integrate into this repo. However, I think we should think of tackling the following:

1. currently the compute capability are in a big list and what can be built depends on the actual CUDA SDK at build time. I'd suggest to create different lists for different SDK.
2. I forgot what I wanted to say... :D

Let me know what you think.