FIX: loosen numerical tolerance in test_pareto()

The problem was that in 32bit Ubuntu 12.04, one gets the following:

>
/home/njs/numpy/.tox/py27/local/lib/python2.7/site-packages/numpy/random/tests/test_random.py(363)test_pareto()
-> np.testing.assert_array_almost_equal(actual, desired, decimal=15)
(Pdb) actual[1, 0]
52828779.702948704
(Pdb) desired[1, 0]
52828779.702948518

and the test was comparing the numbers to 1e-14, which obviously
failed.

Fixes #424.

numpy/random/tests/test_random.py

@@ -360,7 +360,13 @@ def test_pareto(self):
         desired = np.array([[  2.46852460439034849e+03,   1.41286880810518346e+03],
                          [  5.28287797029485181e+07,   6.57720981047328785e+07],
                          [  1.40840323350391515e+02,   1.98390255135251704e+05]])
-        np.testing.assert_array_almost_equal(actual, desired, decimal=15)
+        # For some reason on 32-bit x86 Ubuntu 12.10 the [1, 0] entry in this
+        # matrix differs by 24 nulps. Discussion:
+        #   http://mail.scipy.org/pipermail/numpy-discussion/2012-September/063801.html
+        # Consensus is that this is probably some gcc quirk that affects
+        # rounding but not in any important way, so we just use a looser
+        # tolerance on this test:
+        np.testing.assert_array_almost_equal_nulp(actual, desired, nulp=30)
 
     def test_poisson(self):
         np.random.seed(self.seed)