Allow any 16.x InstallationTarget version

Changed [14.0,16.0] to [14.0,17.0).

Author: jcansdale

src/GitHub.VisualStudio/source.extension.vsixmanifest

@@ -13,8 +13,8 @@
     <Tags>GitHub;git;open source;source control;branch;pull request;team explorer;commit;publish</Tags>
   </Metadata>
   <Installation AllUsers="true" Experimental="false">
-    <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0,16.0]" />
-    <InstallationTarget Id="Microsoft.VisualStudio.IntegratedShell" Version="[15.0,16.0]" />
+    <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0,17.0)" />
+    <InstallationTarget Id="Microsoft.VisualStudio.IntegratedShell" Version="[15.0,17.0)" />
   </Installation>
   <Dependencies>
     <Dependency Id="Microsoft.Framework.NDP" DisplayName="Microsoft .NET Framework" d:Source="Manual" Version="[4.5,)" />