Merge pull request libgit2#4347 from pks-t/pks/appveyor-vs2015

Fix AppVeyor build failures due to CRTDBG linking issue

Author: ethomson

CMakeLists.txt

@@ -173,7 +173,7 @@ IF (MSVC)
 	IF (MSVC_CRTDBG)
 		SET(GIT_MSVC_CRTDBG 1)
 		SET(CRT_FLAG_DEBUG "${CRT_FLAG_DEBUG}")
-		SET(CMAKE_C_STANDARD_LIBRARIES "${CMAKE_C_STANDARD_LIBRARIES}" "Dbghelp.lib")
+		SET(CMAKE_C_STANDARD_LIBRARIES "${CMAKE_C_STANDARD_LIBRARIES} Dbghelp.lib")
 	ENDIF()
 
 	# /Zi - Create debugging information

appveyor.yml

@@ -9,13 +9,23 @@ environment:
   GITTEST_INVASIVE_FS_SIZE: 1
 
   matrix:
-  - GENERATOR: "Visual Studio 11"
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+    GENERATOR: "Visual Studio 10 2010"
     ARCH: 32
-  - GENERATOR: "Visual Studio 11 Win64"
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+    GENERATOR: "Visual Studio 10 2010 Win64"
     ARCH: 64
-  - GENERATOR: "MSYS Makefiles"
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "Visual Studio 14 2015"
+    ARCH: 32
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "Visual Studio 14 2015 Win64"
+    ARCH: 64
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "MSYS Makefiles"
     ARCH: i686 # this is for 32-bit MinGW-w64
-  - GENERATOR: "MSYS Makefiles"
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    GENERATOR: "MSYS Makefiles"
     ARCH: 64
 cache:
 - i686-4.9.2-release-win32-sjlj-rt_v3-rev1.7z