Automatically check `igniter_new` version is latest release.

[frankdugan3]

Is your feature request related to a problem? Please describe.

When running the igniter.new installer, it's easy to forget to check if the installed version is current, especially given how fast Igniter is currently moving.

Describe the solution you'd like

Phoenix recently added a check to the phx.new installer that automatically compares the installed version against the latest release, and warns if it's not up to date.

I think that's a really great idea, and the implementation is pretty simple.

• Maybe rather than just issuing a warning, we would want to ask the user if it should be upgraded and abort, or maybe even automatically upgrade (not sure if that's possible)?
• When using the --with option, perhaps we could check the target installer version?

Additional context

I would be happy to implement this if accepted.

[frankdugan3]

Was just implemented. 🙃