-----------
Added
* ``error_function()``
* ``chi_squared_dist_table()``
* ``bernoulli()``
* ``poisson()``
0.2.5. (2016-09-24)
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Added
* ``harmonic_mean()``
* ``bayesian_classifier()``
* ``perceptron()``
* ``coefficient_of_variation()`` (Thanks to Lidiane Taquehara (lidimayra))
Improved
* Allow user to specify ``sample = False`` in ``tandard_deviation()``,
``coefficient_of_variation()``, ``z_scores()`` (Thanks to Lidiane Taquehara (lidimayra))