Merge pull request netlify#161 from netlify/chore/node-15

chore: support Node 15

Author: ehmicky

.github/workflows/workflow.yml

@@ -15,7 +15,7 @@ jobs:
  os: [ubuntu-latest, macOS-latest, windows-latest]
  # We should test on 10.13.0 but don't due to a bug in Jest
  # https://github.com/facebook/jest/issues/9453
- node-version: [10.15.0, 14.x]
+ node-version: [10.15.0, 15.x]
  exclude:
  - os: macOS-latest
  node-version: 10.15.0