Add a special kind of towncrier type for vendored lib updates

docs/development.rst

@@ -125,6 +125,12 @@ like operating system, one can be added by running
 ``touch news/$(uuidgen).trivial``. Core committers may also add a "trivial"
 label to the PR which will accomplish the same thing.
 
+Upgrading, removing, or adding a new vendored library gets a special mention
+using a ``news/<library>.vendor`` file. This is in addition to any features,
+bugfixes, or other kinds of news that pulling in this library may have. This
+uses the library name as the key so that updating the same library twice doesn't
+produce two news file entries.
+
 
 Release Process
 ===============

news/_template.rst

@@ -13,7 +13,8 @@
 
 {% if definitions[category]['showcontent'] %}
 {% for text, values in sections[section][category]|dictsort(by='value') %}
-- {{ text }} ({{ values|sort|join(', ') }})
+- {{ text }}{% if category != 'vendor' %} ({{ values|sort|join(', ') }}){% endif %}
+
 {% endfor %}
 {% else %}
 - {{ sections[section][category]['']|sort|join(', ') }}

news/appdirs.vendor

+Upgraded appdirs to 1.4.3.

news/cachecontrol.vendor

+Upgraded CacheControl to 0.12.1.

news/distro.vendor

+Upgraded distro to 1.0.2.

news/ipaddress.vendor

+Upgraded ipaddress to 1.0.18.

news/msgpack-python.vendor

+Vendored msgpack-python at 0.4.8.

news/ordereddict.vendor

+Removed the vendored ordereddict.

news/pyparsing.vendor

+Upgraded pyparsing to 2.2.0.

news/requests.vendor

+Upgraded requests to 2.13.0.

news/setuptools.vendor

+Upgraded pkg_resources (via setuptools) to 34.3.2.

pyproject.toml

@@ -23,6 +23,11 @@ template = "news/_template.rst"
   name = "Bug Fixes"
   showcontent = true
 
+  [[tool.towncrier.type]]
+  directory = "vendor"
+  name = "Vendored Libraries"
+  showcontent = true
+
   [[tool.towncrier.type]]
   directory = "doc"
   name = "Improved Documentation"