Prepare for 2020.0.0 release.

Author: drieseng

src/Renci.SshNet/Properties/CommonAssemblyInfo.cs

@@ -11,7 +11,7 @@
 
 [assembly: AssemblyVersion("2020.0.0")]
 [assembly: AssemblyFileVersion("2020.0.0")]
-[assembly: AssemblyInformationalVersion("2020.0.0-beta1")]
+[assembly: AssemblyInformationalVersion("2020.0.0")]
 [assembly: CLSCompliant(false)]
 
 // Setting ComVisible to false makes the types in this assembly not visible