Fix GitHub links

All of these links now redirect to a repo under a different GitHub
user account.

HISTORY.md

@@ -762,9 +762,9 @@ documentation](https://requests.readthedocs.io/en/latest/community/release-proce
 **Features and Improvements**
 
 -   Add sha256 fingerprint support.
-    ([shazow/urllib3\#540](https://github.com/shazow/urllib3/pull/540))
+    ([urllib3/urllib3\#540](https://github.com/urllib3/urllib3/pull/540))
 -   Improve the performance of headers.
-    ([shazow/urllib3\#544](https://github.com/shazow/urllib3/pull/544))
+    ([urllib3/urllib3\#544](https://github.com/urllib3/urllib3/pull/544))
 
 **Bugfixes**
 
@@ -780,19 +780,19 @@ documentation](https://requests.readthedocs.io/en/latest/community/release-proce
     authentication challenges provides both auth and auth-int
     qop-values. (\#2408)
 -   Fix a socket leak.
-    ([shazow/urllib3\#549](https://github.com/shazow/urllib3/pull/549))
+    ([urllib3/urllib3\#549](https://github.com/urllib3/urllib3/pull/549))
 -   Fix multiple `Set-Cookie` headers properly.
-    ([shazow/urllib3\#534](https://github.com/shazow/urllib3/pull/534))
+    ([urllib3/urllib3\#534](https://github.com/urllib3/urllib3/pull/534))
 -   Disable the built-in hostname verification.
-    ([shazow/urllib3\#526](https://github.com/shazow/urllib3/pull/526))
+    ([urllib3/urllib3\#526](https://github.com/urllib3/urllib3/pull/526))
 -   Fix the behaviour of decoding an exhausted stream.
-    ([shazow/urllib3\#535](https://github.com/shazow/urllib3/pull/535))
+    ([urllib3/urllib3\#535](https://github.com/urllib3/urllib3/pull/535))
 
 **Security**
 
 -   Pulled in an updated `cacert.pem`.
 -   Drop RC4 from the default cipher list.
-    ([shazow/urllib3\#551](https://github.com/shazow/urllib3/pull/551))
+    ([urllib3/urllib3\#551](https://github.com/urllib3/urllib3/pull/551))
 
 2.5.1 (2014-12-23)
 ------------------
@@ -1253,7 +1253,7 @@ This is not a backwards compatible change.
 -------------------
 
 -   Removal of Requests.async in favor of
-    [grequests](https://github.com/kennethreitz/grequests)
+    [grequests](https://github.com/spyoungtech/grequests)
 -   Allow disabling of cookie persistence.
 -   New implementation of safe\_mode
 -   cookies.get now supports default argument

docs/community/recommended.rst

@@ -59,4 +59,4 @@ Betamax
 `Betamax`_ records your HTTP interactions so the NSA does not have to.
 A VCR imitation designed only for Python-Requests.
 
-.. _betamax: https://github.com/sigmavirus24/betamax
+.. _betamax: https://github.com/betamaxpy/betamax

docs/user/advanced.rst

@@ -1006,7 +1006,7 @@ library to use SSLv3::
                 block=block, ssl_version=ssl.PROTOCOL_SSLv3)
 
 .. _`described here`: https://www.kennethreitz.org/essays/the-future-of-python-http
-.. _`urllib3`: https://github.com/shazow/urllib3
+.. _`urllib3`: https://github.com/urllib3/urllib3
 
 .. _blocking-or-nonblocking:
 
@@ -1025,7 +1025,7 @@ out there that combine Requests with one of Python's asynchronicity frameworks.
 Some excellent examples are `requests-threads`_, `grequests`_, `requests-futures`_, and `httpx`_.
 
 .. _`requests-threads`: https://github.com/requests/requests-threads
-.. _`grequests`: https://github.com/kennethreitz/grequests
+.. _`grequests`: https://github.com/spyoungtech/grequests
 .. _`requests-futures`: https://github.com/ross/requests-futures
 .. _`httpx`: https://github.com/encode/httpx