some style fixes suggested by pep8-naming
diff --git a/cryptography/hazmat/primitives/asymmetric/rsa.py b/cryptography/hazmat/primitives/asymmetric/rsa.py
index 0121859..23572a5 100644
--- a/cryptography/hazmat/primitives/asymmetric/rsa.py
+++ b/cryptography/hazmat/primitives/asymmetric/rsa.py
@@ -132,7 +132,7 @@
         self._modulus = modulus
 
     @classmethod
-    def generate(self, public_exponent, key_size, backend):
+    def generate(cls, public_exponent, key_size, backend):
         return backend.generate_rsa_private_key(public_exponent, key_size)
 
     @property
diff --git a/cryptography/hazmat/primitives/twofactor/hotp.py b/cryptography/hazmat/primitives/twofactor/hotp.py
index a5c88da..80e2882 100644
--- a/cryptography/hazmat/primitives/twofactor/hotp.py
+++ b/cryptography/hazmat/primitives/twofactor/hotp.py
@@ -52,5 +52,5 @@
         offset_bits = six.indexbytes(hmac_value, 19) & 0b1111
 
         offset = int(offset_bits)
-        P = hmac_value[offset:offset + 4]
-        return struct.unpack(">I", P)[0] & 0x7fffffff
+        p = hmac_value[offset:offset + 4]
+        return struct.unpack(">I", p)[0] & 0x7fffffff
diff --git a/docs/development/submitting-patches.rst b/docs/development/submitting-patches.rst
index 5dca3f7..1797b9c 100644
--- a/docs/development/submitting-patches.rst
+++ b/docs/development/submitting-patches.rst
@@ -15,7 +15,10 @@
 Code
 ----
 
-When in doubt, refer to :pep:`8` for Python code.
+When in doubt, refer to :pep:`8` for Python code. You can check if your code
+meets our automated requirements by running ``flake8`` against it. If you've
+installed the development requirements this will automatically use our
+configuration. You can also run the ``tox`` job with ``tox -e pep8``.
 
 `Write comments as complete sentences.`_
 
diff --git a/setup.py b/setup.py
index 81a50f4..a2a7550 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@
 ]
 
 
-class cffi_build(build):
+class CFFIBuild(build):
     """
     This class exists, instead of just providing ``ext_modules=[...]`` directly
     in ``setup()`` because importing cryptography requires we have several
@@ -110,6 +110,6 @@
     zip_safe=False,
     ext_package="cryptography",
     cmdclass={
-        "build": cffi_build,
+        "build": CFFIBuild,
     }
 )