ci: update config

Author: phatnguyenuit

.github/workflows/ci.yml

@@ -12,8 +12,8 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        node-version: [10.x, 12.x]
-        os: [macos-latest, windows-latest, ubuntu-latest]
+        node-version: [12.x]
+        os: [ubuntu-latest]
     steps:
       - name: Check repository
         uses: actions/checkout@v2