Fix example references to python3 on Windows, where it's only python

Fix #285

examples/azure-pipelines-minimal.yml

@@ -28,8 +28,8 @@ jobs:
     - script: choco install vcpython27 -f -y
       displayName: Install Visual C++ for Python 2.7
     - bash: |
-        python3 -m pip install --upgrade pip
-        pip3 install cibuildwheel==1.1.0
+        python -m pip install --upgrade pip
+        pip install cibuildwheel==1.1.0
         cibuildwheel --output-dir wheelhouse .
     - task: PublishBuildArtifacts@1
       inputs: {pathtoPublish: 'wheelhouse'}

examples/travis-ci-deploy-only.yml

@@ -16,6 +16,8 @@ jobs:
       before_install:
         - choco install python --version 3.8.0
         - export PATH="/c/Python38:/c/Python38/Scripts:$PATH"
+        # make sure it's on PATH as 'python3'
+        - ln -s /c/Python38/python.exe /c/Python38/python3.exe
 
 env:
   global:

examples/travis-ci-minimal.yml

@@ -22,6 +22,8 @@ jobs:
       before_install:
         - choco install python --version 3.8.0
         - export PATH="/c/Python38:/c/Python38/Scripts:$PATH"
+        # make sure it's on PATH as 'python3'
+        - ln -s /c/Python38/python.exe /c/Python38/python3.exe
 
 install:
   - python3 -m pip install cibuildwheel==1.1.0

examples/travis-ci-test-and-deploy.yml

@@ -17,6 +17,8 @@ before_install:
     if [[ "$TRAVIS_OS_NAME" = windows ]]; then
         choco install python --version 3.8.0
         export PATH="/c/Python38:/c/Python38/Scripts:$PATH"
+        # make sure it's on PATH as 'python3'
+        ln -s /c/Python38/python.exe /c/Python38/python3.exe
     fi
 
 install: