Merge pull request #10 from rodo/master

Add unit tests for some functions
Merge pull request #12 from rodo/master

Remove non needed clause in ranks_of/5
bear:statistics_subset/2
Added unit tests for stats_subset
Merge pull request #13 from Feuerlabs/uw-boundary-stats-subset

adjust get_statistics to allow for requesting specific stats to calculate
Add unit test on uncovered function, move test data from src/ to test/