updated yamato editor version

.yamato/environments.yml

 upmci_registry: https://artifactory.prd.cds.internal.unity3d.com/artifactory/api/npm/upm-npm
 
 test_editors:
-  - version: 2019.3.15f1
+  - version: 2019.4.6f1
-  - version: 2019.3.15f1
+  - version: 2019.4.6f1
 
 publish_platforms:
   - name: win