Fallback to npm fails if yarn is outdated

[johnymontana]

Error: node >=12.0.0 required, but found 12.9.1
yarn >=1.15.0 required, but found 1.13.0

Currently if yarn is available but outdated then the fallback to npm fails. Instead of erroring after version check, try fallback to npm

[johnymontana]

Note that the --use-npm flag can be set to force usage of npm