Fix syntax error in appveyor.yml

appveyor.yml

@@ -134,11 +134,11 @@ build_script:
     -I../jansson-%JANSSON_VERSION%/build/include;c:/OpenSSL-Win%PYTHON_ARCH%/include"
 
 after_build:
-  - %PYTHON%\\python setup.py install
+  - "%PYTHON%\\python setup.py install"
 
 test_script:
   # Run the project tests
-  - %PYTHON%\\python setup.py test
+  - "%PYTHON%\\python setup.py test"
 
 after_test:
   # If tests are successful, create binary packages for the project.