Test more Python version on macOS and Windows

Author: pquentin

.appveyor.yml

@@ -8,6 +8,8 @@ environment:
     - PYTHON: "C:\\Python36-x64"
     - PYTHON: "C:\\Python37"
     - PYTHON: "C:\\Python37-x64"
+    - PYTHON: "C:\\Python38"
+    - PYTHON: "C:\\Python38-x64"
 
 build_script:
   - "git --no-pager log -n2"

.travis.yml

@@ -11,7 +11,13 @@ matrix:
     - python: nightly
     - os: osx
       language: generic
-      env: MACPYTHON=3.6.3
+      env: MACPYTHON=3.6.8  # last binary release
+    - os: osx
+      language: generic
+      env: MACPYTHON=3.7.7  # last binary release
+    - os: osx
+      language: generic
+      env: MACPYTHON=3.8.3
     - python: 3.6
       env: CHECK_DOCS=1
     - python: 3.6

ci/travis.sh

@@ -6,7 +6,7 @@ set -ex
 YAPF_VERSION=0.20.0
 
 if [ "$TRAVIS_OS_NAME" = "osx" ]; then
-    curl -Lo macpython.pkg https://www.python.org/ftp/python/${MACPYTHON}/python-${MACPYTHON}-macosx10.6.pkg
+    curl -Lo macpython.pkg https://www.python.org/ftp/python/${MACPYTHON}/python-${MACPYTHON}-macosx10.9.pkg
     sudo installer -pkg macpython.pkg -target /
     ls /Library/Frameworks/Python.framework/Versions/*/bin/
     PYTHON_EXE=/Library/Frameworks/Python.framework/Versions/*/bin/python3