Updated action-deploy-theme to v1.3.1

- hopefully fixes a bug with `theme-name` not being passed through

.github/workflows/deploy-theme.yml

@@ -1,14 +1,14 @@
 name: Deploy Theme
 on:
-  push:	
-    branches:	
+  push:
+    branches:
       - master
 jobs:
   deploy:
     runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
-      - uses: TryGhost/action-deploy-theme@v1.2.1
+      - uses: TryGhost/action-deploy-theme@v1.3.1
         with:
           api-url: ${{ secrets.GHOST_ADMIN_API_URL }}
           api-key: ${{ secrets.GHOST_ADMIN_API_KEY }}