dropped macos, windows, and node 10

.github/workflows/nodejs.yml

@@ -4,19 +4,14 @@ on: [push, pull_request]
 
 jobs:
   build-node:
-    runs-on: ${{ matrix.os }}
-
-    strategy:
-      matrix:
-        node-version: [10.x, 12.x]
-        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v1
-      - name: Use Node.js ${{ matrix.node-version }}
+      - name: Use Node.js 12.x
         uses: actions/setup-node@v1
         with:
-          node-version: ${{ matrix.node-version }}
+          node-version: 12.x
       - name: Get npm cache directory
         id: npm-cache
         run: |