Remove extra targets from vsix completely

Author: shana

src/GitHub.VisualStudio/source.extension.vsixmanifest

@@ -12,9 +12,6 @@
   </Metadata>
   <Installation AllUsers="true">
     <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0,]" />
-    <InstallationTarget Id="Microsoft.VisualStudio.VSWinDesktopExpress" Version="[14.0,)" />
-    <InstallationTarget Id="Microsoft.VisualStudio.VSWinExpress" Version="[14.0,)" />
-    <InstallationTarget Id="Microsoft.VisualStudio.VWDExpress" Version="[14.0,)" />
   </Installation>
   <Dependencies>
     <Dependency Id="Microsoft.Framework.NDP" DisplayName="Microsoft .NET Framework" d:Source="Manual" Version="[4.5,)" />