New option to allow for 'Ignored' migrations in 'validate' command: ignoreIgnoredMigrations

[bkaminnski]

This is a pull request for issue #1865.

The main change was done in MigrationInfoImpl class, where the new configuration flag is actually checked. All other changes are done taking as an example "flyway.ignoreMissingMigrations" configuration flag. I added a new option: "flyway.ignoreIgnoredMigrations". All changes in code take place next to a "missing" boolean flag.

I tried to follow all the conventions already applied in code. Also description of the configuration option in flyway.conf was done so that it is as similar to the description of surrounding "ignore..." flags, as possible.

[CLAassistant]

All committers have signed the CLA.

[axelfontaine]

Thanks. This looks great! Could you also make the necessary changes to the Maven and Gradle plugins?

[bkaminnski]

Done. Sorry I missed that. I also added info message to command-line help and checked that it now shows up. I haven't run flyway as maven nor gradle plugin though. Could you please let me know whether you have a quick way to verify that? I can do this, but I need little more time to set up maven and gradle plugin in my environment to make sure that this new flag is properly picked up also here.

[axelfontaine]

Looking good!

All that is left now is the docs. Could you submit a pull request against the flyway-5.1.0 branch of flyway/flywaydb.org ? Thanks!

[bkaminnski]

Done. What I noticed during update of documentation:

1. I missed handling of FLYWAY_IGNORE_IGNORED_MIGRATIONS in env variables in ConfigUtils. Fixed in another commit in pull request.
2. I updated 3 undo.md files (commandline, gradle and maven) - this is however not covered by opensource version, and I am not sure how this relates to my change.
3. I skipped release notes and javadoc.

[axelfontaine]

Thank you very much for the great work! Merged. I have also taken the liberty to add you to the Hall of Fame page (flyway-5.1.0 branch).