appveyor: legacy build on win32

.appveyor.yml

 version: 1.0.{build}
 os: Visual Studio 2015
 clone_folder: C:\projects\pybind11
+test: off
 branches:
   only:
     - master
+environment:
+  matrix:
+    - CMAKE_PLATFORM: "Visual Studio 14 2015"
+      PYTHON_DIR: "C:\\Python34"
+    - CMAKE_PLATFORM: "Visual Studio 14 2015 Win64"
+      PYTHON_DIR: "C:\\Python34-x64"
 install:
   - cinstall: python
 build_script:
   - echo Running cmake...
   - cd c:\projects\pybind11
-  - cmake -G "Visual Studio 14 2015 Win64" -DPYTHON_INCLUDE_DIR:PATH=C:/Python34-x64/include -DPYTHON_LIBRARY:FILEPATH=C:/Python34-x64/libs/python34.lib -DPYTHON_EXECUTABLE:FILEPATH=C:/Python34-x64/python.exe
+  - cmake -G "%CMAKE_PLATFORM%" -DPYTHON_INCLUDE_DIR:PATH=%PYTHON_DIR%/include -DPYTHON_LIBRARY:FILEPATH=%PYTHON_DIR%/libs/python34.lib -DPYTHON_EXECUTABLE:FILEPATH=%PYTHON_DIR%/python.exe
   - set MSBuildLogger="C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
   - set MSBuildOptions=/v:m /p:Configuration=Release /logger:%MSBuildLogger%
   - msbuild %MSBuildOptions% pybind11.sln