Update SECURITY.md to reflect support for version 2.0.x

Author: Lyzev

SECURITY.md

@@ -6,7 +6,7 @@ The following versions of the project are currently being supported with securit
 
 | Version | Supported          |
 |---------|--------------------|
-| 1.2.x   | :white_check_mark: |
+| 2.0.x   | :white_check_mark: |
 | 1.1.x   | :x:                |
 | 1.0.x   | :x:                |