add appveyor CI config

appveyor.yml

@@ -0,0 +1,74 @@
+# https://www.appveyor.com/docs/appveyor-yml/
+environment:
+
+  # SDK v7.0 MSVC Express 2008's SetEnv.cmd script will fail if the
+  # /E:ON and /V:ON options are not enabled in the batch script interpreter
+  # See: http://stackoverflow.com/a/13751649/163740
+  CMD_IN_ENV: "cmd /E:ON /V:ON /C obvci_appveyor_python_build_env.cmd"
+
+  matrix:
+    # Pre-installed Python versions, which Appveyor may upgrade to
+    # a later point release.
+    # See: http://www.appveyor.com/docs/installed-software#python
+
+    - PYTHON: "C:\\Python27"
+      PYTHON_VERSION: "2.7.x"
+      PYTHON_ARCH: "32"
+      TOXENV: "py27"
+
+    - PYTHON: "C:\\Python27-x64"
+      PYTHON_VERSION: "2.7.x"
+      PYTHON_ARCH: "64"
+      TOXENV: "py27"
+
+    - PYTHON: "C:\\Python35"
+      PYTHON_VERSION: "3.5.x"
+      PYTHON_ARCH: "32"
+      TOXENV: "py35"
+
+    - PYTHON: "C:\\Python35-x64"
+      PYTHON_VERSION: "3.5.x"
+      PYTHON_ARCH: "64"
+      TOXENV: "py35"
+
+    - PYTHON: "C:\\Python36-x64"
+      PYTHON_VERSION: "3.6.x"
+      PYTHON_ARCH: "64"
+      TOXENV: "py36"
+
+    - PYTHON: "C:\\Python37-x64"
+      PYTHON_VERSION: "3.7.x"
+      PYTHON_ARCH: "64"
+      TOXENV: "py37"
+
+build: off
+
+# https://www.appveyor.com/docs/build-cache/
+cache:
+  - C:\ProgramData\chocolatey\bin -> appveyor.yml
+  - C:\ProgramData\chocolatey\lib -> appveyor.yml
+  - '%LOCALAPPDATA%\pip\Cache -> appveyor.yml'
+
+# scripts that run after cloning repository
+install:
+  # If there is a newer build queued for the same PR, cancel this one.
+  # The AppVeyor 'rollout builds' option is supposed to serve the same
+  # purpose but it is problematic because it tends to cancel builds pushed
+  # directly to master instead of just PR builds (or the converse).
+  - SET path=%PYTHON%;%PYTHON%\\Scripts;%path%
+  - python -m pip install --upgrade pip
+  - pip install tox tox-pip-version
+
+# scripts to run before tests (working directory and environment changes are persisted from the previous steps such as "before_build")
+before_test:
+  - python --version
+  - pip --version
+  - pip list
+  - dir
+
+# to run your custom scripts instead of automatic tests
+test_script:
+  - tox --parallel auto
+
+on_success:
+  - coverage report

tox.ini

@@ -7,6 +7,7 @@ deps =
 
 [testenv]
 usedevelop=True
+pip_version = pip>=18.0
 
 deps =
     {[base]deps}