#129 Update Node.js version of test workflow

Author: astropenguin

.github/workflows/tests.yml

@@ -24,7 +24,7 @@ jobs:
           python-version: ${{ matrix.python }}
       - uses: actions/setup-node@v2
         with:
-          node-version: "15"
+          node-version: "lts/gallium"
       - name: Install project dependencies
         run: pip install poetry && poetry install && npm install
       - name: Test code's formatting (Black)