Update master merge yml names

.github/workflows/stable-merge.yml

@@ -1,4 +1,4 @@
-name: 'Stable Merge'
+name: 'Master Merge'
 
 on:
     push:
@@ -6,7 +6,7 @@ on:
         - master
 
 jobs:
-  nightly-merge:
+  master-merge:
 
     runs-on: ubuntu-latest
 
@@ -14,7 +14,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v1
 
-    - name: Nightly Merge
+    - name: Merge master into dev
       uses: robotology/gh-action-nightly-merge@v1.2.0
       with:
         stable_branch: 'master'