Add appveyor tests

appveyor.yml

@@ -0,0 +1,34 @@
+environment:
+  PROJECT_FOLDER: "c:/yaml-cpp"
+  INSTALL_PREFIX: "c:/install"
+
+# Operating system (build VM template)
+os: Visual Studio 2015
+
+# scripts that are called at very beginning, before repo cloning
+init:
+
+
+# clone directory
+clone_folder: "%PROJECT_FOLDER%"
+
+platform:
+  - x86
+  - x64
+
+configuration:
+  - Debug
+  - Release
+
+install:
+
+# scripts to run before build
+before_build:
+  - cmake . -DCMAKE_INSTALL_PREFIX=%INSTALL_PREFIX%
+
+# What solutions to build
+build:
+  project: ALL_BUILD.vcxproj
+
+test_script: 
+  - ctest -V