update tox

Author: Ben Cipollini

tox.ini

@@ -18,3 +18,8 @@ deps =
 deps =
 [testenv:np-1.2.1]
 deps =
+[flake8]
+max-line-length=100
+ignore=D100,D101,D102,D103,D104,D105,D200,D201,D204,D205,D208,D210,D300,D301,D400,D401,D403,E266,E402,E731,F821,I100,I101,I201,N802,N803,N804,N806
+exclude=*test*,*sphinx*,nibabel/externals/*,*/__init__.py
+