Merge pull request #1163 from bkoehm/bkoehm.7.0.x.casdoc

remove references to Grails 3 from CAS plugin documentation

Author: jamesfredley

plugin-cas/docs/src/docs/usage.adoc

@@ -31,8 +31,6 @@ https://www.jasig.org/cas[CAS] is a popular single sign-on implementation. It's
 
 There isn't much that you need to do in your application to be a CAS client. Add a dependency in `build.gradle` for this plugin:
 
-If you are using 3.3.x use:
-
 [source,groovy]
 [subs="attributes"]
 .build.gradle
@@ -43,21 +41,6 @@ dependencies {
    ...
 ----
 
-If you are using Grails 3.0.x 3.1.x or 3.2.x use:
-
-[source,groovy]
-[subs="attributes"]
-.build.gradle
-----
-dependencies {
-   ...
-   implementation 'org.apache.grails:grails-spring-security-cas:{threeZeroXProjectVersion}'
-   ...
-----
-
-
-
-
 then configure any required parameters and whatever optional parameters you want in application.yml or application.groovy. These are described in detail in the <<configuration>> section but typically you only need to set these properties:
 
 [source,yaml]