Fixed prerequisite

Author: ThomasArdal

src/CronExpressionsVsix/source.extension.vsixmanifest

@@ -22,6 +22,6 @@
         <Asset Type="Microsoft.VisualStudio.MefComponent" d:Source="Project" d:ProjectName="CronExpressions.Analyers" Path="|CronExpressions.Analyers|" />
     </Assets>
     <Prerequisites>
-        <Prerequisite Id="Microsoft.VisualStudio.Component.CoreEditor" Version="[17.0,18.0)" DisplayName="Visual Studio core editor" />
+        <Prerequisite Id="Microsoft.VisualStudio.Component.CoreEditor" Version="[17.0,19.0)" DisplayName="Visual Studio core editor" />
     </Prerequisites>
 </PackageManifest>