doctest needed a teardown fixture, pep8 work

this was the real fix for #316, not sure why this did not show up when
testing on linux mint

setup.py

@@ -21,6 +21,7 @@ kwargs = {'name': 'Glymur',
           'test_suite': 'glymur.test'}
 
 install_requires = ['numpy>=1.7.0', 'lxml>=3.0.0']
+test_requires = []
 if sys.hexversion < 0x03030000:
     install_requires.append('contextlib2>=0.4')
     test_requires.append('mock>=1.0.1')