tests: Update test coverage to Python 3.9

The Travis Linux distribution must be upgraded because the Trusty
(Ubuntu 14.04) image does not have Python 3.9. Xenial (Ubuntu 16.04) is
the earliest version that offers Python 3.9.

I have not chosen a later release, in order to aid restoration of Python
2.4 - 2.6 tests.

.ci/azure-pipelines.yml

@@ -66,6 +66,12 @@ jobs:
         DISTRO: debian
         VER: 2.10.0
 
+      Mito39Debian_27:
+        python.version: '3.9'
+        MODE: mitogen
+        DISTRO: debian
+        VER: 2.10.0
+
       #Py26CentOS7:
         #python.version: '2.7'
         #MODE: mitogen
@@ -117,3 +123,8 @@ jobs:
         python.version: '3.5'
         MODE: ansible
         VER: 2.10.0
+
+      Ansible_210_39:
+        python.version: '3.9'
+        MODE: ansible
+        VER: 2.10.0

.travis.yml

@@ -1,5 +1,5 @@
 sudo: required
-dist: trusty
+dist: xenial  # Ubuntu 16.04 LTS
 
 notifications:
   email: false
@@ -17,7 +17,6 @@ cache:
   - /home/travis/virtualenv
 
 install:
-- grep -Erl git-lfs\|couchdb /etc/apt | sudo xargs rm -v
 - pip install -U pip==20.2.1
 - .ci/${MODE}_install.py
 
@@ -53,6 +52,9 @@ matrix:
     - python: "3.6"
       env: MODE=ansible VER=2.10.0
     # 2.10 -> {debian, centos6, centos7}
+    - python: "3.9"
+      env: MODE=ansible VER=2.10.0
+    # 2.10 -> {debian, centos6, centos7}
     - python: "2.7"
       env: MODE=ansible VER=2.10.0
     # 2.10 -> {debian, centos6, centos7}
@@ -73,6 +75,8 @@ matrix:
       #env: MODE=mitogen DISTRO=centos6
     - python: "3.6"
       env: MODE=mitogen DISTROS=centos7 VER=2.10.0
+    - python: "3.9"
+      env: MODE=mitogen DISTROS=centos7 VER=2.10.0
     # 2.6 -> 2.7
     # - python: "2.6"
     #   env: MODE=mitogen DISTROS=centos7 VER=2.10.0

docs/changelog.rst

@@ -40,6 +40,7 @@ v0.2.10 (unreleased)
   timeout, when using recent OpenSSH client versions.
 * :gh:issue:`758` fix initilialisation of callback plugins in test suite, to address a `KeyError` in
   :method:`ansible.plugins.callback.CallbackBase.v2_runner_on_start`
+* :gh:issue:`775` Test with Python 3.9
 
 
 v0.2.9 (2019-11-02)

tests/ansible/requirements.txt

@@ -1,4 +1,4 @@
 paramiko==2.3.2  # Last 2.6-compat version.
 hdrhistogram==0.6.1
 PyYAML==3.11; python_version < '2.7'
-PyYAML==3.13; python_version >= '2.7'
+PyYAML==5.3.1; python_version >= '2.7'  # Latest release (Jan 2021)