Integrate Gradle Enterprise plugin

Closes gh-20

settings.gradle

@@ -1,3 +1,15 @@
+pluginManagement {
+	repositories {
+		gradlePluginPortal()
+		maven { url 'https://repo.spring.io/plugins-release' }
+	}
+}
+
+plugins {
+	id "com.gradle.enterprise" version "3.2"
+	id "io.spring.gradle-enterprise-conventions" version "0.0.2"
+}
+
 rootProject.name = 'spring-authorization-server'
 
 FileTree buildFiles = fileTree(rootDir) {