try enabling CI with Windows

.travis.yml

@@ -71,6 +71,24 @@ matrix:
         env: TOX_ENV=pypy
       - python: pypy3
         env: TOX_ENV=pypy3
+      # We use explicit version as the PATH needs major-minor part
+      - name: "Python3.8.0 on Windows"
+        os: windows
+        language: shell
+        before_install:
+          - choco install python --version 3.8.0
+          - python -m pip install --upgrade pip
+        env: PATH=/c/Python38:/c/Python38/Scripts:$PATH
+        install:
+          - pip list
+          - pip install six
+          - pip install -r build-requirements.txt
+          - pip list
+        script:
+          - pytest src/ecdsa
+        after_success:
+          - coveralls
+
   allow_failures:
       - python: nightly