add build on AppVeyor

appveyor.yml

@@ -0,0 +1,28 @@
+build: false
+shallow_clone: true
+
+cache:
+  - .\php -> appveyor.yml
+  - vendor -> composer.lock
+
+init:
+  - set PATH=%PATH%;.\php
+  - set COMPOSER_NO_INTERACTION=1
+  - set CACHED=0
+
+install:
+  - if exist .\php (set CACHED=1) else (mkdir .\php)
+  - if %CACHED%==0 cd .\php
+  - if %CACHED%==0 appveyor DownloadFile http://windows.php.net/downloads/releases/archives/php-7.1.8-nts-Win32-VC14-x64.zip -FileName php.zip
+  - if %CACHED%==0 appveyor DownloadFile https://getcomposer.org/composer.phar
+  - if %CACHED%==0 7z x php.zip -y
+  - if %CACHED%==0 copy php.ini-production php.ini /Y
+  - if %CACHED%==0 echo date.timezone="Europe/Berlin" >> php.ini
+  - if %CACHED%==0 echo extension_dir=ext >> php.ini
+  - if %CACHED%==0 echo extension=php_openssl.dll >> php.ini
+  - if %CACHED%==0 echo extension=php_mbstring.dll >> php.ini
+  - if %CACHED%==0 cd ..
+
+test_script:
+  - php .\php\composer.phar install
+  - vendor/bin/phpunit.bat --coverage-text