Update publish.yml (#2040)

Author: tomchristie

.github/workflows/publish.yml

@@ -1,4 +1,3 @@
----
 name: Publish
 
 on:
@@ -11,6 +10,9 @@ jobs:
     name: "Publish release"
     runs-on: "ubuntu-latest"
 
+    environment:
+       name: deploy
+
     steps:
       - uses: "actions/checkout@v2"
       - uses: "actions/setup-python@v1"