Merge pull request #8 from froque/visual-studio-2019-support

Edit vsixmanifest to support Visual Studio 2019 (16.0)

Author: froque

VSIXInteropFormsToolkit/source.extension.vsixmanifest

@@ -7,7 +7,7 @@
     </Metadata>
     <Installation>
         <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0]" />
-        <InstallationTarget Version="[15.0,16.0)" Id="Microsoft.VisualStudio.Community" />
+        <InstallationTarget Version="[15.0,17.0)" Id="Microsoft.VisualStudio.Community" />
     </Installation>
     <Dependencies>
         <Dependency Id="Microsoft.Framework.NDP" DisplayName="Microsoft .NET Framework" d:Source="Manual" Version="[4.5,)" />
@@ -17,6 +17,6 @@
         <Asset Type="Microsoft.VisualStudio.VsPackage" d:Source="Project" d:ProjectName="%CurrentProject%" Path="|%CurrentProject%;PkgdefProjectOutputGroup|" />
     </Assets>
     <Prerequisites>
-        <Prerequisite Id="Microsoft.VisualStudio.Component.CoreEditor" Version="[15.0,16.0)" DisplayName="Visual Studio core editor" />
+        <Prerequisite Id="Microsoft.VisualStudio.Component.CoreEditor" Version="[15.0,17.0)" DisplayName="Visual Studio core editor" />
     </Prerequisites>
 </PackageManifest>