CHANGE: add 6.1 to CI & readme for recipe regeneration exception (#2111)

Author: stefanunity

.yamato/config.metadata

@@ -4,6 +4,8 @@ editors:
     disable_tvos_run: true
   - version: 6000.0
     disable_tvos_run: true
+  - version: 6000.1
+    disable_tvos_run: true
   - version: trunk
     disable_tvos_run: true
 

Tools/CI/README_AFTER_REGENERATION.md

@@ -0,0 +1,4 @@
+After you regenerate the yamato jobs you need to make the following edit:
+
+In .yamato\wrench\validation-jobs.yml find "validate_-_inputsystem_-_2019_4_-_ubuntu"-job and change
+"image: package-ci/ubuntu-20.04:default" to "image: package-ci/ubuntu-18.04:v4"