Add tests
Add PGM examples but i'm not sure it gives correct answers yet.

Need a unit test for the pgm stuff
Flattening nested distributions with mapcat
Fixed the tail recursion issue
Representing distributions for Bayesian networks as hash-maps
Updated sampling given a predicate. Added some more stuff for the grass network.
Fixed probability function
changed true/false predicate and updated examples
Probability function corrected and debug keyword added. Examples updated.
changed sampling in given
Examples updates and changes to probability computation.
More efficient sampling for PGMs

Using frequencies and list comprehension in sample for PGMs. Also
replaced reduce with core.reducers fold when possible.
Changed number of samples in probability computation
EPL licensing
Using Metropolis-Hasting sampling for PGM-type distributions

Using Timbre for logging
Sampling works properly now

The rain example is good to go. Must fix the traffic example.
Renaming project to Watershed and edited README.
commented out some old stuff that will be revisited and fixed a bug i introduced recently
Moved predicates to their own namespace and updated README
removed some obsolete code from examples