Require Visual Studio 2015.
We no longer need or use Visual Studio 2013.
https://ci.appveyor.com/project/jrfonseca/mesa/build/52
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
diff --git a/docs/install.html b/docs/install.html
index d3c53d1..49a8806 100644
--- a/docs/install.html
+++ b/docs/install.html
@@ -57,7 +57,7 @@
<ul>
<li>GCC 4.2.0 or later (some parts of Mesa may require later versions)
<li>clang - exact minimum requirement is currently unknown.
-<li>Microsoft Visual Studio 2013 Update 4 or later is required, for building on Windows.
+<li>Microsoft Visual Studio 2015 or later is required, for building on Windows.
</ul>