Add Python 3.9 support; drop 3.5 support.

Author: freakboy3742

README.rst

@@ -27,20 +27,21 @@ The master branch of this repository has no content; there is an
 independent branch for each supported version of Python. The following
 Python versions are supported:
 
-* `Python 3.5 <https://github.com/pybee/Python-Apple-support/tree/3.5>`__
-* `Python 3.6 <https://github.com/pybee/Python-Apple-support/tree/3.6>`__
-* `Python 3.7 <https://github.com/pybee/Python-Apple-support/tree/3.7>`__
-* `Python 3.8 <https://github.com/pybee/Python-Apple-support/tree/3.8>`__
+* `Python 3.6 <https://github.com/beeware/Python-Apple-support/tree/3.6>`__
+* `Python 3.7 <https://github.com/beeware/Python-Apple-support/tree/3.7>`__
+* `Python 3.8 <https://github.com/beeware/Python-Apple-support/tree/3.8>`__
+* `Python 3.9 <https://github.com/beeware/Python-Apple-support/tree/3.9>`__
 
 Suggestions for changes should be made against the `dev branch
 <https://github.com/beeware/Python-Apple-support/tree/dev>`__; these
 will then be backported into the supported Python releases. The dev branch will
-track the most recent supported version of Python (currently, Python 3.8).
+track the most recent supported version of Python (currently, Python 3.9).
 
 See the individual branches for usage instructions.
 
 The following versions were supported in the past, but are no longer
 maintained:
 
-* `Python 2.7 <https://github.com/pybee/Python-Apple-support/tree/2.7>`__ (EOL January 2020)
-* `Python 3.4 <https://github.com/pybee/Python-Apple-support/tree/3.4>`__ (EOL March 2019)
+* `Python 2.7 <https://github.com/beeware/Python-Apple-support/tree/2.7>`__ (EOL January 2020)
+* `Python 3.4 <https://github.com/beeware/Python-Apple-support/tree/3.4>`__ (EOL March 2019)
+* `Python 3.5 <https://github.com/beeware/Python-Apple-support/tree/3.5>`__ (EOL February 2021)