STY: Simplify flake8 rules; fix issue found

Author: effigies

nibabel/nifti1.py

@@ -524,9 +524,6 @@ def get_sizeondisk(self):
     def __repr__(self):
         return "Nifti1Extensions(%s)" % ', '.join(str(e) for e in self)
 
-    def __cmp__(self, other):
-        return cmp(list(self), list(other))
-
     def write_to(self, fileobj, byteswap):
         """ Write header extensions to fileobj
 

setup.cfg

@@ -40,7 +40,7 @@ all =
 
 [flake8]
 max-line-length = 100
-ignore = D100,D101,D102,D103,D104,D105,D200,D201,D202,D204,D205,D208,D209,D210,D300,D301,D400,D401,D403,E24,E121,E123,E126,E226,E266,E402,E704,E731,F821,I100,I101,I201,N802,N803,N804,N806,W503,W504,W605
+extend-ignore = E203,E266,E402,E731
 exclude =
     *test*
     *sphinx*