Update creatingCustomCommands.adoc

[johan313]

trafficstars

Class grails.cli.GrailsApplicationCommand does not exist. Based on other recently updated commands the correct class is grails.dev.commands.GrailsApplicationCommand

Tested and worked.

First ever PR here, I hope the process is lean.

[CLAassistant]

All committers have signed the CLA.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[sdelamo]

@johan313 you need to sign the contributor license agreement?

[johan313]

For me it says on Jun 22:

CLA assistant check All committers have signed the CLA.

[johan313]

I signed again - lets see if it is now OK.

[matrei]

There seems to be something wrong with the CLA signing. I'm gonna merge this, thanks @johan313 👍