Allow milestone dependencies for compatibility testing of a release

Author: wilkinsona

build.gradle

@@ -9,8 +9,13 @@ allprojects {
 	group = "org.springframework.restdocs"
 	repositories {
 		mavenCentral()
-		if (version.contains('-')) {
-			maven { url "https://repo.spring.io/milestone" }
+		maven {
+			url "https://repo.spring.io/milestone"
+			content {
+				includeGroup "io.micrometer"
+				includeGroup "io.projectreactor"
+				includeGroup "org.springframework"
+			}
 		}
 		if (version.endsWith('-SNAPSHOT')) {
 			maven { url "https://repo.spring.io/snapshot" }