Merge remote-tracking branch 'origin/branch5.0'

docs/releases.rst

@@ -4,6 +4,7 @@ Release notes
 .. toctree::
    :maxdepth: 2
 
+   releases/v5.0.1
    releases/v5.0.0
    releases/v4.5.3
    releases/v4.5.2

docs/releases/v5.0.1.rst

+What's new in Tornado 5.0.1
+===========================
+
+Mar 18, 2018
+------------
+
+Bug fix
+~~~~~~~
+
+- This release restores support for versions of Python 3.4 prior to
+  3.4.4. This is important for compatibility with Debian Jessie which
+  has 3.4.2 as its version of Python 3.