add appveyor.yml
diff --git a/appveyor.yml b/appveyor.yml
new file mode 100644
index 0000000..990e8e6
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,6 @@
+build_script:
+  - mkdir build
+  - cd build
+  - cmake -DCMAKE_BUILD_TYPE=RELEASE -G "NMake Makefiles" ..
+  - nmake
+