Update AppVeyor configuration

Create AppVeyor batch script and move CI scripts to a separate folder.

.travis.yml

@@ -7,7 +7,7 @@ before_install:
   - git submodule update --init --recursive
 install:
   # source because it sets up env vars on some platforms
-  - source travis/travis_install.sh
+  - source ci/travis/travis_install.sh
 script: ./run_tests.py
 env:
   matrix:

appveyor.yml

@@ -2,15 +2,17 @@ version: '{build}'
 environment:
   matrix:
   - arch: 32
+    python: 35
+  # We only test Python 2.7 on 64 bits.
   - arch: 64
+    python: 27
+  - arch: 64
+    python: 35
 install:
-  - git submodule update --init --recursive
-  - ps: $env:python = if ($env:arch -eq 32) { 'C:\Python27' } else { 'C:\Python27-x64' }
-  - appveyor DownloadFile https://bootstrap.pypa.io/get-pip.py
-  - set PATH=%python%;%python%\Scripts;%PATH%
-  - python get-pip.py
-  - pip install -r python\test_requirements.txt
+  - ci\appveyor\appveyor_install.bat
 build_script:
   - python run_tests.py
 # Disable automatic tests
 test: off
+cache:
+  - '%LOCALAPPDATA%\pip\cache'  # Python packages from pip

ci/appveyor/appveyor_install.bat

@@ -0,0 +1,29 @@
+git submodule update --init --recursive
+:: Batch script will not exit if a command returns an error, so we manually do
+:: it for commands that may fail.
+if %errorlevel% neq 0 exit /b %errorlevel%
+
+::
+:: Python configuration
+::
+
+if %arch% == 32 (
+  set python_path=C:\Python%python%
+) else (
+  set python_path=C:\Python%python%-x64
+)
+
+set PATH=%python_path%;%python_path%\Scripts;%PATH%
+python --version
+
+:: When using Python 3 on AppVeyor, CMake will always pick the 64 bits
+:: libraries. We specifically tell CMake the right path to the libraries
+:: according to the architecture.
+if %python% == 35 (
+  set EXTRA_CMAKE_ARGS="-DPYTHON_LIBRARY=%python_path%\libs\python%python%.lib"
+)
+
+appveyor DownloadFile https://bootstrap.pypa.io/get-pip.py
+python get-pip.py
+pip install -r python\test_requirements.txt
+if %errorlevel% neq 0 exit /b %errorlevel%

ci/travis/travis_install.sh

@@ -9,7 +9,7 @@ set -ev
 # Requirements of OS-specific install:
 #  - install any software which is not installed by Travis configuration
 #  - set up everything necessary so that pyenv can build python
-source travis/travis_install.${TRAVIS_OS_NAME}.sh
+source ci/travis/travis_install.${TRAVIS_OS_NAME}.sh
 
 #############
 # pyenv setup