Merge pull request #1263 from alex/wordwrap-and-check

Linewrap CHANGELOG and have doc8 check it as well
diff --git a/docs/hazmat/primitives/mac/cmac.rst b/docs/hazmat/primitives/mac/cmac.rst
index 104ba8b..1ba1b3f 100644
--- a/docs/hazmat/primitives/mac/cmac.rst
+++ b/docs/hazmat/primitives/mac/cmac.rst
@@ -31,7 +31,7 @@
         >>> from cryptography.hazmat.primitives.ciphers import algorithms
         >>> c = cmac.CMAC(algorithms.AES(key), backend=default_backend())
         >>> c.update(b"message to authenticate")
-        >>> c.copy().finalize()
+        >>> c.finalize()
         'CT\x1d\xc8\x0e\x15\xbe4e\xdb\xb6\x84\xca\xd9Xk'
 
     If the backend doesn't support the requested ``algorithm`` an
@@ -47,6 +47,8 @@
 
     .. doctest::
 
+        >>> c = cmac.CMAC(algorithms.AES(key), backend=default_backend())
+        >>> c.update(b"message to authenticate")
         >>> c.verify(b"an incorrect signature")
         Traceback (most recent call last):
         ...
diff --git a/docs/hazmat/primitives/mac/hmac.rst b/docs/hazmat/primitives/mac/hmac.rst
index da75fa9..9ce49c8 100644
--- a/docs/hazmat/primitives/mac/hmac.rst
+++ b/docs/hazmat/primitives/mac/hmac.rst
@@ -31,7 +31,7 @@
         >>> from cryptography.hazmat.primitives import hashes, hmac
         >>> h = hmac.HMAC(key, hashes.SHA256(), backend=default_backend())
         >>> h.update(b"message to hash")
-        >>> h.copy().finalize()
+        >>> h.finalize()
         '#F\xdaI\x8b"e\xc4\xf1\xbb\x9a\x8fc\xff\xf5\xdex.\xbc\xcd/+\x8a\x86\x1d\x84\'\xc3\xa6\x1d\xd8J'
 
     If the backend doesn't support the requested ``algorithm`` an
@@ -47,6 +47,8 @@
 
     .. doctest::
 
+        >>> h = hmac.HMAC(key, hashes.SHA256(), backend=default_backend())
+        >>> h.update(b"message to hash")
         >>> h.verify(b"an incorrect signature")
         Traceback (most recent call last):
         ...
diff --git a/docs/random-numbers.rst b/docs/random-numbers.rst
index 410f375..68a72cf 100644
--- a/docs/random-numbers.rst
+++ b/docs/random-numbers.rst
@@ -16,7 +16,6 @@
 .. doctest::
 
     >>> import os
-    >>> os.urandom(16)
-    '...'
+    >>> iv = os.urandom(16)
 
 .. _`always use your operating system's provided random number generator`: http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/