Explicitly declare Stein supported runtimes

This adds a PTI section to have an official declaration of
the targeted runtimes for the release. This should also be retroactively
added to other cycle sections so we have a historical record of what was
supported for that release.

Javascript section omitted because I have zero experience with Node and
NPM, but it would be good to expand on this to include all of our
official runtimes.

Change-Id: I11b136a9781dd1a77df536f099df10a6dd524e06
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>

reference/project-testing-interface.rst

@@ -107,6 +107,8 @@ being emitted into ``releasenotes/build/html``.
 
 Language specific instructions supplement these and are in addition to them.
 
+.. _pti-linux-distros:
+
 Linux Distributions
 -------------------
 
@@ -141,3 +143,21 @@ tests might have to be skipped on these distributions.
    :glob:
 
    pti/*
+
+.. _pti-tested-runtimes:
+
+Tested Runtimes
+---------------
+
+In order to focus development efforts and prevent breaking changes midway
+through a development cycle, the policy for officially tested runtimes is
+based on the LTS or stable release of the :ref:`pti-linux-distros` at the start of
+the development cycle.
+
+The officially tested runtimes for each cycle can be found here:
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   runtimes/*

reference/pti/golang.rst

@@ -1,3 +1,5 @@
+.. _pti-golang:
+
 =============================
 Project Testing Interface: Go
 =============================

reference/pti/python.rst

@@ -7,16 +7,13 @@ Project Testing Interface: Python
 Each python project must be able to do:
 
 - Unit tests for python2.7
+- Unit tests for python3 (see below for version details)
 - Codestyle checks
 - Testing Coverage Report
 - Source Tarball Generation
 - Translations import/export and merge for translated projects
 - Documentation generation
 
-Projects which are compatible with Python 3 must also be able to do:
-
-- Unit tests for python3.5
-
 Specific commands
 -----------------
 
@@ -30,15 +27,17 @@ tree:
 - ``python setup.py bdist_wheel``
 - ``sphinx-build -W -b html doc/source doc/build``
 
+The Python 3 version may change from cycle to cycle. Projects should
+target the following, replacing `3x` with the :ref:`tested Python 3 runtimes
+<pti-tested-runtimes>` for the current development cycle:
+
+- ``tox -e py3x``
+
 Projects that are translated should also support:
 
 - ``tox -e venv python setup.py extract_messages``
 - ``tox -e venv python setup.py update_catalog``
 
-Projects which are compatible with Python 3 must also be able to do:
-
-- ``tox -e py35``
-
 Some basic prerequisites for test running (system packages, database
 configuration, custom filesystem types) are acceptable as long as they are
 documented in a visible location such as a CONTRIBUTING, TESTING, or README

reference/runtimes/stein.rst

@@ -0,0 +1,33 @@
+=========================
+Tested Runtimes for Stein
+=========================
+
+It is the policy that each OpenStack release cycle will target the
+currently available runtimes on the :ref:`LTS or stable
+distributions <pti-linux-distros>` at the start of a development cycle.
+
+At the start of the Stein development cycle, the current versions are:
+
+* Ubuntu 18.04
+* CentOS 7
+
+Python Runtime for Stein
+========================
+
+Based on the available Python runtimes for the supported Linux distributions,
+all Python-based projects must target and test against, at a minimum:
+
+* Python 2.7
+* Python 3.6
+
+More details on Python requirements can be found in :ref:`pti-python`.
+
+Golang Runtime for Stein
+========================
+
+At this time, there are still frequent releases of Go with a wide variety of
+distribution packaged versions. Given the current state of Go support and the
+number of projects within OpenStack using Go, no formal version declaration is
+being made at this time.
+
+More details on Go requirements can be found in :ref:`pti-golang`.