AppVeyor: explicitly select worker image

Currently, we're using the default Visual Studio 2015 image for
everything.

Closes https://github.com/curl/curl/pull/3606

diff --git a/appveyor.yml b/appveyor.yml
index ff8043040851264550b6b5d979ee3e971232cdf0..99ec8706876d6d3206dd08e96d8d1cf69fd86442 100644 (file)
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -2,42 +2,48 @@ version: 7.50.0.{build}
 
 environment:
     matrix:
-      - PRJ_GEN: "Visual Studio 9 2008"
+      - APPVEYOR_BUILD_WORKER_IMAGE: "Visual Studio 2015"
+        PRJ_GEN: "Visual Studio 9 2008"
         PRJ_CFG: Release
         OPENSSL: OFF
         WINSSL: ON
         HTTP_ONLY: OFF
         TESTING: OFF
         SHARED: ON
-      - PRJ_GEN: "Visual Studio 14 2015 Win64"
+      - APPVEYOR_BUILD_WORKER_IMAGE: "Visual Studio 2015"
+        PRJ_GEN: "Visual Studio 14 2015 Win64"
         PRJ_CFG: Release
         OPENSSL: OFF
         WINSSL: ON
         HTTP_ONLY: OFF
         TESTING: OFF
         SHARED: ON
-      - PRJ_GEN: "Visual Studio 14 2015 Win64"
+      - APPVEYOR_BUILD_WORKER_IMAGE: "Visual Studio 2015"
+        PRJ_GEN: "Visual Studio 14 2015 Win64"
         PRJ_CFG: Release
         OPENSSL: ON
         WINSSL: OFF
         HTTP_ONLY: OFF
         TESTING: OFF
         SHARED: ON
-      - PRJ_GEN: "Visual Studio 10 2010 Win64"
+      - APPVEYOR_BUILD_WORKER_IMAGE: "Visual Studio 2015"
+        PRJ_GEN: "Visual Studio 10 2010 Win64"
         PRJ_CFG: Debug
         OPENSSL: OFF
         WINSSL: OFF
         HTTP_ONLY: OFF
         TESTING: ON
         SHARED: OFF
-      - PRJ_GEN: "Visual Studio 14 2015 Win64"
+      - APPVEYOR_BUILD_WORKER_IMAGE: "Visual Studio 2015"
+        PRJ_GEN: "Visual Studio 14 2015 Win64"
         PRJ_CFG: Debug
         OPENSSL: OFF
         WINSSL: OFF
         HTTP_ONLY: OFF
         TESTING: ON
         SHARED: OFF
-      - PRJ_GEN: "Visual Studio 14 2015 Win64"
+      - APPVEYOR_BUILD_WORKER_IMAGE: "Visual Studio 2015"
+        PRJ_GEN: "Visual Studio 14 2015 Win64"
         PRJ_CFG: Debug
         OPENSSL: OFF
         WINSSL: OFF