Remove some AppVeyor envs that are available on GitHub Actions
diff --git a/appveyor.yml b/appveyor.yml
index 1464615..564a665 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -4,16 +4,12 @@
   matrix:
     - PYTHON_EXE: "C:\\Python26\\python.exe"
     - PYTHON_EXE: "C:\\Python26-x64\\python.exe"
-    - PYTHON_EXE: "C:\\Python27\\python.exe"
-    - PYTHON_EXE: "C:\\Python27\\python.exe"
+    - PYTHON_EXE: "C:\\Python26-x64\\python.exe"
       OSCRYPTO_USE_WINLEGACY: "true"
-    - PYTHON_EXE: "C:\\Python27-x64\\python.exe"
     - PYTHON_EXE: "C:\\Python33\\python.exe"
     - PYTHON_EXE: "C:\\Python33\\python.exe"
       OSCRYPTO_USE_WINLEGACY: "true"
     - PYTHON_EXE: "C:\\Python33-x64\\python.exe"
-    - PYTHON_EXE: "C:\\Python36\\python.exe"
-    - PYTHON_EXE: "C:\\Python36-x64\\python.exe"
     - PYTHON_EXE: "C:\\pypy2-v5.10.0-win32\\pypy.exe"
     - PYTHON_EXE: "C:\\pypy2-v5.10.0-win32\\pypy.exe"
       OSCRYPTO_USE_WINLEGACY: "true"