CI: Drop 2.7, 3.4 tests from AppVeyor

Author: effigies

appveyor.yml

@@ -4,10 +4,6 @@
 environment:
 
   matrix:
-    - PYTHON: C:\Python27
-    - PYTHON: C:\Python27-x64
-    - PYTHON: C:\Python34
-    - PYTHON: C:\Python34-x64
     - PYTHON: C:\Python35
     - PYTHON: C:\Python35-x64
     - PYTHON: C:\Python36