Reverted a few spelling changes

Based on feedback on pull request #534 on GitHub

Closes #534

Author: IanLee1521

pycodestyle.py

@@ -122,7 +122,7 @@
 LAMBDA_REGEX = re.compile(r'\blambda\b')
 HUNK_REGEX = re.compile(r'^@@ -\d+(?:,\d+)? \+(\d+)(?:,(\d+))? @@.*$')
 
-# Work around Python < 2.6 behavior, which does not generate NL after
+# Work around Python < 2.6 behaviour, which does not generate NL after
 # a comment which is on a line by itself.
 COMMENT_WITH_NL = tokenize.generate_tokens(['#\n'].pop).send(None)[1] == '#\n'
 

testsuite/test_api.py

@@ -138,7 +138,7 @@ def test_styleguide(self):
         self.reset()
 
     def test_styleguide_options(self):
-        # Instanstiate a simple checker
+        # Instantiate a simple checker
         pep8style = pycodestyle.StyleGuide(paths=[E11])
 
         # Check style's attributes