Use Visual Studio 2015 by default for development

Author: sharwell

Build/build.ps1

@@ -1,6 +1,6 @@
 param (
 	[switch]$Debug,
-	[string]$VisualStudioVersion = "12.0",
+	[string]$VisualStudioVersion = "14.0",
 	[switch]$NoDocs,
 	[string]$Verbosity = "normal",
 	[string]$Logger,

Rackspace.Threading.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 2013
-VisualStudioVersion = 12.0.30501.0
+# Visual Studio 14
+VisualStudioVersion = 14.0.23107.0
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Rackspace.Threading.net35-client", "Rackspace.Threading\Rackspace.Threading.net35-client.csproj", "{52CA4A3B-F296-4489-B5F0-AD375D039B35}"
 EndProject

appveyor.yml

@@ -1,4 +1,5 @@
 version: 1.0.{build}
+os: Visual Studio 2015
 configuration: Release
 environment:
   DELAY_TOLERANCE_MS: 50
@@ -7,7 +8,7 @@ init:
 - git config --global core.autocrlf true
 build_script:
 - cd build
-- powershell -Command .\build.ps1 -VisualStudioVersion "12.0" -InstallSHFB -Verbosity minimal -Logger "${env:ProgramFiles}\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
+- powershell -Command .\build.ps1 -VisualStudioVersion "14.0" -InstallSHFB -Verbosity minimal -Logger "${env:ProgramFiles}\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
 - cd ..
 after_build:
 - cd build