Declare that 2.1 is the last version to support Python 2.6 (#3944)

* Declare that 2.1 is the last version to support Python 2.6

* It's the Final Countdown!
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 91e450b..81aab1b 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -9,6 +9,8 @@
 
 .. note:: This version is not yet released and is under active development.
 
+* **FINAL DEPRECATION** Python 2.6 support is deprecated, and will be removed
+  in the next release of ``cryptography``.
 * **BACKWARDS INCOMPATIBLE:** ``Whirlpool``, ``RIPEMD160``, and
   ``UnsupportedExtension`` have been removed in accordance with our
   :doc:`/api-stability` policy.
diff --git a/docs/installation.rst b/docs/installation.rst
index 51caefd..7066865 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -22,8 +22,8 @@
 * 32-bit and 64-bit Python on 64-bit Windows Server 2012
 
 .. warning::
-    Python 2.6 is no longer supported by the Python core team. A future version
-    of cryptography will drop support for this version.
+    Python 2.6 is no longer supported by the Python core team. The next release
+    of ``cryptography`` will drop support for Python 2.6.
 
 We test compiling with ``clang`` as well as ``gcc`` and use the following
 OpenSSL releases:
diff --git a/src/cryptography/__init__.py b/src/cryptography/__init__.py
index 940c66b..e5c34a2 100644
--- a/src/cryptography/__init__.py
+++ b/src/cryptography/__init__.py
@@ -21,7 +21,7 @@
 if sys.version_info[:2] == (2, 6):
     warnings.warn(
         "Python 2.6 is no longer supported by the Python core team, please "
-        "upgrade your Python. A future version of cryptography will drop "
+        "upgrade your Python. The next version of cryptography will drop "
         "support for Python 2.6",
         DeprecationWarning
     )