Closes #13944: fix capitalization of class name.

Doc/library/hmac.rst

@@ -25,29 +25,28 @@ This module implements the HMAC algorithm as described by :rfc:`2104`.
 
 An HMAC object has the following methods:
 
-
-.. method:: hmac.update(msg)
+.. method:: HMAC.update(msg)
 
    Update the hmac object with the string *msg*.  Repeated calls are equivalent to
    a single call with the concatenation of all the arguments: ``m.update(a);
    m.update(b)`` is equivalent to ``m.update(a + b)``.
 
 
-.. method:: hmac.digest()
+.. method:: HMAC.digest()
 
    Return the digest of the strings passed to the :meth:`update` method so far.
    This string will be the same length as the *digest_size* of the digest given to
    the constructor.  It may contain non-ASCII characters, including NUL bytes.
 
 
-.. method:: hmac.hexdigest()
+.. method:: HMAC.hexdigest()
 
    Like :meth:`digest` except the digest is returned as a string twice the length
    containing only hexadecimal digits.  This may be used to exchange the value
    safely in email or other non-binary environments.
 
 
-.. method:: hmac.copy()
+.. method:: HMAC.copy()
 
    Return a copy ("clone") of the hmac object.  This can be used to efficiently
    compute the digests of strings that share a common initial substring.