message: workflows: prevent coveralls JS out of memory
  This is an attempt to prevent the coveralls error:
  FATAL ERROR: Ineffective mark-compacts near heap limit Allocation
  failed - JavaScript heap out of memory
diff: @@ -15,6 +15,8 @@ jobs:
  coverage:
  name: coverage (ubuntu-18.04)
  runs-on: ubuntu-18.04
  + env:
  + NODE_OPTIONS: --max_old_space_size=4096
  steps:
  - uses: actions/checkout@v2
  with:
  