Review and fix sample projects licenses

[l0rd]

Is your enhancement related to a problem?

From @amisevsk comment:

Many of the projects in devfiles currently do not contain a LICENSE file. Projects that do not have an license:

Anything in the che-samples repositories but notably

• https://github.com/che-samples/aspnetcore-realworld-example-app (forked from gothinkster)
• https://github.com/che-samples/django-realworld-example-app (forked from gothinkster)
• https://github.com/gothinkster/angular-realworld-example-app
• https://github.com/gothinkster/laravel-realworld-example-app
• https://github.com/gothinkster/react-redux-realworld-example-app
• https://github.com/xesina/golang-echo-realworld-example-app
• https://github.com/spring-projects/spring-petclinic (no license file but has license section in README.md)

Describe the solution you'd like

• Review the licenses for all the sample projects in the devfile registry
• Add license for the projects we have created
• Open issues to replace projects that have an incompatible license or do not have license at all

[amisevsk]

While reviewing the che-samples projects, it's worth double checking for #13593 as well, as that issue has gone unaddressed thus far.

[amisevsk]

PR eclipse-che/che-devfile-registry#96 adds another gothinkster sample to the devfile registry.

[che-bot]

Issues go stale after 180 days of inactivity. lifecycle/stale issues rot after an additional 7 days of inactivity and eventually close.

Mark the issue as fresh with /remove-lifecycle stale in a new comment.

If this issue is safe to close now please do so.

Moderators: Add lifecycle/frozen label to avoid stale mode.

[amisevsk]

/remove-lifecycle stale