Multi distance sampling

• Added support for sampling with multiple distance simultaneously
• Clean setup.py
• Simplifying the code
• Improved documentation

Py3 + fixes

• Python 3 support
• Minor fixes
• Improved documentation

First public release

• Entirely implemented in Python and easy to extend
• Follows Beaumont et al. 2009 PMC algorithm
• Parallelized with muliprocessing or message passing interface (MPI)
• Extendable with k-nearest neighbour (KNN) or optimal local covariance matrix (OLCM) pertubation kernels (Fillipi et al. 2012)
• Detailed examples in IPython notebooks