Tests fail on OSX

[cap]

Running CC=clang PYDISTRIBUTIONS_USE_LIB=1 make test on OSX, I see these errors:

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FAIL: distributions.tests.test_clustering.test_models(<type 'distributions.lp.clustering.PitmanYor'>, 5)
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Traceback (most recent call last):
  File "/Users/cpetschulat/.virtualenvs/pk/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/Users/cpetschulat/src/distributions/distributions/tests/test_clustering.py", line 97, in _test_models
    'not normalized: {}'.format(total))
AssertionError: not normalized: 0.989162792478
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Example 0
    Prob    Count
   0.200      190 ------------------------------------------------------------
   0.050       63 --------------------
   0.050       53 -----------------
   0.050       52 ----------------
   0.050       42 -------------
   0.050       40 -------------
   0.017       22 -------
   0.017       21 -------
PitmanYor gof = 0.214
Example 1
    Prob    Count
   0.161      151 ------------------------------------------------------------
   0.045       61 ------------------------
   0.045       52 ---------------------
   0.045       47 -------------------
   0.045       45 ------------------
   0.045       49 -------------------
   0.020       20 --------
   0.019       22 ---------
PitmanYor gof = 0.412
Example 2
    Prob    Count
   0.755      763 ------------------------------------------------------------
   0.016       18 -
   0.016       18 -
   0.016       15 -
   0.016       11 -
   0.016       15 -
   0.016       15 -
   0.016       14 -
PitmanYor gof = 0.919
Example 3

--------------------- >> end captured stdout << ----------------------

======================================================================
FAIL: distributions.tests.test_models.test_sample_group('lp.models.dpd',)
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Traceback (most recent call last):
  File "/Users/cpetschulat/.virtualenvs/pk/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/Users/cpetschulat/src/distributions/distributions/tests/test_models.py", line 95, in test_one_model
    test_fun(Model, EXAMPLE)
  File "/Users/cpetschulat/src/distributions/distributions/tests/test_models.py", line 292, in test_sample_group
    assert_greater(gof, MIN_GOODNESS_OF_FIT)
AssertionError: 1.4720371676952502e-06 not greater than 0.001
-------------------- >> begin captured stdout << ---------------------
example 1/1
    Prob    Count
   0.417      368 ------------------------------------------------------------
   0.188      195 --------------------------------
   0.188      187 ------------------------------
   0.042       65 -----------
   0.042       56 ---------
   0.042       48 --------
   0.042       30 -----
   0.021       34 ------
DirichletProcessDiscrete gof = 1.47e-06

--------------------- >> end captured stdout << ----------------------