chore: drop Node.js 10 support

[dhmlau]

Signed-off-by: Diana Lau [email protected]

Node.js 10 has reached EOL April 2020, see https://nodejs.org/en/about/releases/. We're dropping the support for Node.js 10.

Note: We need to get GitHub Actions working for CI. I'm running tests locally for now.

Checklist

• [x] DCO (Developer Certificate of Origin) signed in all commits
• [x] npm test passes on your machine
• [ ] New tests added or existing tests modified to cover all changes
• [x] Code conforms with the style guide
• [x] Commit messages are following our guidelines

[dhmlau]

@marioestradarosa, I wasn't intended to update the keywords, since it has LoopBack in it. But I'm open for suggestions.