Update version of yargs to address security issue

[jwoudenberg]

This addresses a security issue with mem, which is a dependency of os-locale, which is a dependency of yargs, which is a dependency of elm-verify-examples. Unfortunately addressing the issue requires us to update yargs two major versions.

Luckily the major versions don't seem to introduce a whole bunch of breaking changes and, as far as I can see, none relevant for elm-verify-examples.

Related issue in the yargs repo: https://github.com/yargs/yargs/pull/1270

Yargs changelog: https://github.com/yargs/yargs/blob/master/CHANGELOG.md

Breaking changes in version 13.x

• options with leading '+' or '0' now parse as strings
• dropping Node 6 which hits end of life in April 2019
• we now warn if the yargs stanza package.json is used.

Breaking changes in version 12.x:

• Options absent from argv (not set via CLI argument) are now absent from the parsed result object rather than being set with undefined
• drop Node 4 from testing matrix, such that we'll gradually start drifting away from supporting Node 4.
• yargs-parser does not populate 'false' when boolean flag is not passed
• tests that assert against help output will need to be updated

[jwoudenberg]

Thank you! Would it be possible to do a release with these changes? I want to move a project to this version to get rid of a security warning.

[stoeffel]

Published with elm-verify-examples@4.0.1.