Not going to bother with a test_requires section. Closes #51.

Numpy causes trouble on the mac with test_requires.  Anyway, the only
real hard requirement is "mock" with 2.6 and 2.7, and that's hardly
worth the extra trouble.  matplotlib and pillow are optional requirements.

setup.py

@@ -16,19 +16,15 @@ kwargs = {'name': 'Glymur',
           'test_suite': 'glymur.test',
           'platforms': ['darwin']}
 
-instllrqrs = ['numpy>1.6.2']
+instllrqrs = ['numpy>=1.4.1']
 if sys.hexversion < 0x03030000:
     instllrqrs.append('contextlib2>=0.4')
+    instllrqrs.append('mock>=1.0.1')
 if sys.hexversion < 0x02070000:
     instllrqrs.append('ordereddict>=1.1')
     instllrqrs.append('unittest2>=0.5.1')
 kwargs['install_requires'] = instllrqrs
 
-testrqrs = ['matplotlib>=1.1.0', 'Pillow>=2.0.0']
-if sys.hexversion < 0x03030000:
-    testrqrs.append('mock>=1.0.1')
-kwargs['tests_require'] = testrqrs
-
 clssfrs = ["Programming Language :: Python",
            "Programming Language :: Python :: 2.6",
            "Programming Language :: Python :: 2.7",