v0.1.0, 5/21/15 -- Initial release.
v0.1.1, 5/21/15 -- Updated readme, docstrings, and unit tests.
v0.1.2, 5/21/15 -- Added documentation and examples.
v0.1.3, 5/21/15 -- data_files missing.
v0.1.4, 5/21/15 -- Improved documentation and examples work on python 2.
v0.1.5, 5/21/15 -- Improving documentation and provided fast example.
v0.1.6, 5/21/15 -- Updated code so that it appears to be working on python 2.
v0.1.7, 5/28/15 -- Slight refactoring to remove numpy import in utils. 
v0.1.8, 5/29/15 -- Added __future__ to example_utils.py
v0.1.9, 5/30/15 -- Upddated pointer management and cobweb3 normalization
v0.2.0, 7/28/15 -- Rewrote structure mapper and changed instance representation
v0.2.1, 7/28/15 -- Updated structure mapping code to align with changes in
                   py_search
v0.2.2, 7/30/15 -- Updated structure mapping code to align with more changes
                   py_search
v0.2.3, 7/30/15 -- Increased version requirement to fix bug in py_search
v0.2.4, 7/30/15 -- Updated structure mapping code to improve performance
v0.2.5, 7/30/15 -- Bug in structure mapping code corrected
v0.2.5, 7/30/15 -- Updated action planner.
v0.2.6, 8/2/15  -- Fixed bug in structure mapping rewards computation
v0.2.7, 8/7/15  -- Updated action planner.
v0.2.8, 8/10/15 -- Updated action planner.
v0.2.9, 8/10/15 -- Fixed action planner bug.
v0.2.10,8/11/15 -- Fixed action planner bug.
v0.2.11,8/11/15 -- Action planner ignores hidden.
v0.2.12,8/17/15 -- Removed action planner and updated infer_missing
v0.2.13,8/17/15 -- Fixed bug in cobweb3 that converts bools to numerics
v0.2.14,8/18/15 -- Fixed bug in cobweb3 that threw KeyErrors in infer_missing
v0.2.15,8/18/15 -- Fixed bug introduced in previous fix
v0.2.17,1/28/16 -- Categorize now uses a matching score between instance and
                   concept. Also, get_probability and get_probability missing
                   were updated to take into account new attr values with
                   laplace smoothing.
v0.2.18,1/28/16 -- Fixed error in infer_missing that gave higher chance of
                   missing.
v0.2.19,1/28/16 -- Changed categorize function to use the concept that most
                   closely matches the instance (max # of correct guesses in
                   instance). Also, added cobweb3 regression example. 
v0.3.0, 7/27/16 -- Improved docs, added tests, improved speed and performance
                   of structure mapper.
v0.3.1, 6/17/17 -- Made improvement to underlying Cobweb algorithm to improve
                   time complexity of categorizing with / updating the tree.
                   Also, fixed bug in the probabilities returned for continuous
                   values.
v0.3.2, 6/17/17 -- Accidentally pushed experimental numpy version to pypi in
                   v0.3.1, this is the latest non-experimental version.
v0.3.4, 4/16/18 -- Updated cluster visulization.
