How to compile widgetset for CKEditor addon with Gradle?

I’m using Vaadin 7.7.7 which I thought didn’t require compiling widgetsets as per

However, when I try to use the CKEditor addon!addon/ckeditor-wrapper-for-vaadin I get the following error where the compontent is put:

Widgetset ‘com.vaadin.DefaultWidgetSet’ does not contain an implementation for org.vaadin.openesignforms.ckeditor.CKEditorTextField. Check the connector’s @Connect mapping, the widgetset’s GWT module description file and re-compile your widgetset. In case you have downloaded a vaadin add-on package, you might want to refer to

I’ve simply added the addon to my

compile(‘org.vaadin.addons:ckeditor-wrapper-for-vaadin:7.11.1’) { exclude group:‘com.vaadin’ }

The documentation for the add-on (above link) states "
You simply can drop the JAR file into your Vaadin WEB-INF/lib and begin using it, but as for all new add-ons, do a Vaadin widgetset compile
.", however I’m quite new to Vaadin and do not know how to do that with Gradle.

Other things may worth noting is that I’m using Vaadin with Spring Boot, and have included Vaadin as a dependency using the default from
Spring Initializr

dependencyManagement { imports { mavenBom “com.vaadin:vaadin-bom:7.7.7” }

Does anyone care to enlighten me please?