Travis: run selftest on Windows

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/.travis.yml b/.travis.yml
index cdb79d1..ace1e5c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -79,6 +79,7 @@
         # Logs appear out of sequence on Windows. Give time to catch up.
         - sleep 5
         - scripts/windows_msbuild.bat v141 # Visual Studio 2017
+        - visualc/VS2013/x64/Release/selftest.exe
 
     - name: full configuration on arm64
       os: linux