make builds time out after a reasonable period (#5100)

.github/workflows/ci.yml

@@ -3,6 +3,7 @@ on: [push, pull_request]
 jobs:
   Tests:
     runs-on: ${{ matrix.os }}
+    timeout-minutes: 6
     strategy:
       matrix:
         node-version: [8, 10, 12, 14]
@@ -18,12 +19,14 @@ jobs:
         CI: true
   Lint:
     runs-on: ubuntu-latest
+    timeout-minutes: 2
     steps:
     - uses: actions/checkout@v1
     - uses: actions/setup-node@v1
     - run: 'npm i && npm run lint'
   Unit:
     runs-on: ${{ matrix.os }}
+    timeout-minutes: 3
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macOS-latest]