engine should not be set to only "8"
engine should not be set to only "8"

Tried to install `resume-cli` this morning and received an error:

    `error resume-schema@0.0.17: The engine "node" is incompatible with this module. Expected version "8". Got "11.5.0"`

The engine in resume-cli [package.json] (https://github.com/jsonresume/resume-cli/blob/master/package.json) is `^8`

This should be at least be compatible:
    `^version “Compatible with version” See semver`
jsonresume/resume-schema