Prevent runtime incompatibility with 'early-semver'

Now that both content-api-models and content-api-scala-client are both
using 'early-semver' and adhering to it (thanks to
gha-scala-library-release-workflow and sbt-version-policy) this should
mean that it is **no longer possible** for a single project that depends
on content-api-scala-client, content-api-models and facia-scala-client
to have _incompatible_ versions of those artifacts.

guardian/content-api-scala-client#405

fapi-client/src/test/scala/com/gu/facia/api/TestModel.scala

@@ -191,6 +191,7 @@ object TestModel {
     tags: Seq[StubTag],
     elements: Option[Seq[StubElement]]
   ) extends Content {
+    val channels: Option[Seq[ContentChannel]] = None // alternatively, create StubContentChannel
     def `type`: ContentType = ContentType.list.find(byName(typeName)(_)).get
     def sectionId: Option[String] = None
     def sectionName: Option[String] = None

project/dependencies.scala

@@ -1,7 +1,7 @@
 import sbt._
 
 object Dependencies {
-  val capiVersion = "21.0.0"
+  val capiVersion = "22.0.0"
 
   val awsSdk = "com.amazonaws" % "aws-java-sdk-s3" % "1.12.524"
   val commonsIo = "org.apache.commons" % "commons-io" % "1.3.2"