Merge pull request #4126 from radarhere/python38

Added Python 3.8 rc1 to AppVeyor

.appveyor.yml

@@ -34,9 +34,15 @@ environment:
     EXECUTABLE: bin/pypy.exe
     PIP_DIR: bin
     VENV: YES
+  - PYTHON: C:\Python38rc1-x64
 
 
 install:
+- ps: |
+      if ($env:PYTHON -eq "C:\Python38rc1-x64") {
+        curl -o install_python.ps1 https://raw.githubusercontent.com/matthew-brett/multibuild/d0cf77e62028704875073e3dc4626f61d1c33b0e/install_python.ps1
+        .\install_python.ps1
+      }
 - curl -fsSL -o pillow-depends.zip https://github.com/python-pillow/pillow-depends/archive/master.zip
 - 7z x pillow-depends.zip -oc:\
 - mv c:\pillow-depends-master c:\pillow-depends

winbuild/config.py

@@ -10,6 +10,7 @@ pythons = {
     "36": {"compiler": 7.1, "vc": 2015},
     "pypy3": {"compiler": 7.1, "vc": 2015},
     "37": {"compiler": 7.1, "vc": 2015},
+    "38rc1-x64": {"compiler": 7.1, "vc": 2015},
 }
 
 VIRT_BASE = "c:/vp/"