Adding manual Python 3.8 installation to appveyor.yml and azure-pipelines.yml

Author: YannickJadoul

appveyor.yml

@@ -4,6 +4,10 @@ environment:
     - PYTHON: "C:\\Python35\\python.exe"
 
 build_script:
+  - ps: 
+      curl -o install_python.ps1 https://raw.githubusercontent.com/matthew-brett/multibuild/11a389d78892cf90addac8f69433d5e22bfa422a/install_python.ps1
+      & { $env:PYTHON = 'C:\\Python38'; .\install_python.ps1 }
+      & { $env:PYTHON = 'C:\\Python38-x64'; .\install_python.ps1 }
   - "%PYTHON% -m pip install -r requirements-dev.txt"
   # the '-u' flag is required so the output is in the correct order. 
   # See https://github.com/joerick/cibuildwheel/pull/24 for more info.

azure-pipelines.yml

@@ -26,8 +26,12 @@ jobs:
     - {task: UsePythonVersion@0, inputs: {versionSpec: '3.6', architecture: x64}}
     - {task: UsePythonVersion@0, inputs: {versionSpec: '3.7', architecture: x86}}
     - {task: UsePythonVersion@0, inputs: {versionSpec: '3.7', architecture: x64}}
-    - {task: UsePythonVersion@0, inputs: {versionSpec: '3.8', architecture: x86}}
-    - {task: UsePythonVersion@0, inputs: {versionSpec: '3.8', architecture: x64}}
+    #- {task: UsePythonVersion@0, inputs: {versionSpec: '3.8', architecture: x86}}
+    #- {task: UsePythonVersion@0, inputs: {versionSpec: '3.8', architecture: x64}}
+    - powershell: |
+        curl -o install_python.ps1 https://raw.githubusercontent.com/matthew-brett/multibuild/11a389d78892cf90addac8f69433d5e22bfa422a/install_python.ps1
+        & { $env:PYTHON = 'C:\\Python38'; .\install_python.ps1; Copy-Item 'C:\\Python38' 'C:\\hostedtoolcache\\windows\\Python\\3.8.0\\x86' -Recurse }
+        & { $env:PYTHON = 'C:\\Python38-x64'; .\install_python.ps1; Copy-Item 'C:\\Python38-x64' 'C:\\hostedtoolcache\\windows\\Python\\3.8.0\\x64' -Recurse }
     - script: choco install vcpython27 -f -y
       displayName: Install Visual C++ for Python 2.7
     - bash: |