update to node 12 lts version

Author: JamesKyburz

.github/workflows/benchmarks.yml

@@ -13,7 +13,7 @@ jobs:
     - name: Use Node.js ${{ matrix.node-version }}
       uses: actions/setup-node@v1
       with:
-        node-version: 10
+        node-version: 12
     - name: benchmarks
       run: |
         npm install