MAINT: drop numpy 1.5 compatibility code in sparse matrix tests
BUG: make sparse conjugate gradient benchmark, added in gh-4306, run.
Merge pull request #4315 from argriffing/check-differential-entropy

MAINT: drop numpy 1.5 compatibility code in sparse matrix tests
MAINT: fix hamming distance regression for exotic arrays, with unit test
TST: a few changes like self.assertTrue(x == y, message) -> assert_equal(x, y)
TST: more changes like self.assertTrue(x == y, message) -> assert_equal(x, y)
TST: in test_signaltools, changes like self.assertTrue(x == y, message) -> assert_equal(x, y)
Merge pull request #4320 from argriffing/test-assertion-syntax

TST: a few changes like self.assertTrue(x == y, message) -> assert_equal(x, y)
Merge pull request #4322 from argriffing/test-assertion-syntax-c

TST: in test_signaltools, changes like self.assertTrue(x == y, message) -> assert_equal(x, y)
Merge pull request #4319 from argriffing/revisit-hamming

MAINT: fix hamming distance regression for exotic arrays, with unit test
TST: assert_(x < y) -> assert_array_less(x, y)
TST: use numpy.testing in test_hierarchy.py
Merge pull request #4321 from argriffing/test-assertion-syntax-b

TST: more changes like self.assertTrue(x == y, message) -> assert_equal(x, y)
Merge pull request #4326 from argriffing/update-hierarchy-tests

TST: use numpy.testing in test_hierarchy.py
Merge branch 'master' into betaprime