Fix remove testing matrix, one environment is enough

Author: Bassem Dghaidi

.github/workflows/publish.yml

@@ -9,16 +9,13 @@ jobs:
   npm-publish:
     name: npm-publish
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        node-version: [10.x, 12.x]
     steps:
     - name: Checkout repository
       uses: actions/checkout@master
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
+    - name: Set up Node.js
+      uses: actions/setup-node@master
       with:
-        node-version: ${{ matrix.node-version }}
+        node-version: 10.0.0
     - name: Publish if version has been updated
       uses: pascalgn/npm-publish-action@4f4bf159e299f65d21cd1cbd96fc5d53228036df
       with: # All of theses inputs are optional