Add appveyor.yml to test VS2015 builds.

Signed-off-by: Ralph Giles <giles@thaumas.net>
diff --git a/appveyor.yml b/appveyor.yml
new file mode 100644
index 0000000..c419edb
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,19 @@
+image: Visual Studio 2015
+configuration:
+- Debug
+- Release
+
+platform:
+- Win32
+- x64
+
+build:
+  project: win32\VS2015\libogg_static.sln
+  parallel: true
+  verbosity: minimal
+
+after_build:
+- cmd: 7z a ogg.zip win32\VS2015\%PLATFORM%\%CONFIGURATION%\libogg_static.lib include\ogg\*.h
+
+artifacts:
+- path: ogg.zip