Upgraded the VS solution to VS2017 format

Author: leekelleher

src/Our.Umbraco.Ditto.sln

@@ -1,6 +1,7 @@
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.25123.0
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.27004.2009
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Our.Umbraco.Ditto", "Our.Umbraco.Ditto\Our.Umbraco.Ditto.csproj", "{3A2482A4-AD19-4C26-A449-4287DA07AB16}"
 EndProject
@@ -14,8 +15,8 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Build Package", "Build Package", "{302C02F0-CA95-430F-BD43-82D0CCEC08A3}"
 	ProjectSection(SolutionItems) = preProject
 		..\appveyor.yml = ..\appveyor.yml
-		..\build.cmd = ..\build.cmd
 		..\build\build-appveyor.cmd = ..\build\build-appveyor.cmd
+		..\build.cmd = ..\build.cmd
 		..\build\package.nuspec = ..\build\package.nuspec
 		..\build\package.proj = ..\build\package.proj
 		..\build\package.xml = ..\build\package.xml
@@ -69,4 +70,7 @@ Global
 		{302C02F0-CA95-430F-BD43-82D0CCEC08A3} = {6CF4E7DA-6359-479E-A64D-2023C743BA1C}
 		{8A5424A2-03F9-4D89-9B68-CB286D7F8596} = {6CF4E7DA-6359-479E-A64D-2023C743BA1C}
 	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {8C9C786C-59D5-42E5-9FAA-97E3936DBAED}
+	EndGlobalSection
 EndGlobal