Bump version to v12.2.0

Author: tsnoam

CHANGES.rst

@@ -2,6 +2,33 @@
 Changelog
 =========
 
+Version 12.2.0
+==============
+
+**New features:**
+
+- Nested ConversationHandlers (`#1512`_).
+
+**Minor changes, CI improvments or bug fixes:**
+
+- Fix CI failures due to non-backward compat attrs depndency (`#1540`_).
+- travis.yaml: TEST_OFFICIAL removed from allowed_failures.
+- Fix typos in examples (`#1537`_).
+- Fix Bot.to_dict to use proper first_name (`#1525`_).
+- Refactor ``test_commandhandler.py`` (`#1408`_).
+- Add Python 3.8 (RC version) to Travis testing matrix (`#1543`_).
+- test_bot.py: Add to_dict test (`#1544`_).
+- Flake config moved into setup.cfg (`#1546`_).
+
+.. _`#1512`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1512
+.. _`#1540`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1540
+.. _`#1537`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1537
+.. _`#1525`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1525
+.. _`#1408`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1408
+.. _`#1543`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1543
+.. _`#1544`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1544
+.. _`#1546`: https://github.com/python-telegram-bot/python-telegram-bot/pull/1546
+
 Version 12.1.1
 ==============
 *Released 2019-09-18*

docs/source/conf.py

@@ -60,7 +60,7 @@
 # The short X.Y version.
 version = '12.1'  # telegram.__version__[:3]
 # The full version, including alpha/beta/rc tags.
-release = '12.1.1'  # telegram.__version__
+release = '12.2.0'  # telegram.__version__
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

telegram/version.py

@@ -17,4 +17,4 @@
 # You should have received a copy of the GNU Lesser Public License
 # along with this program.  If not, see [http://www.gnu.org/licenses/].
 
-__version__ = '12.1.1'
+__version__ = '12.2.0'