Add nohttp check to build. Upgrade gradle and asciidoctor plugin.

build.gradle

@@ -9,8 +9,9 @@ buildscript {
 	}
 	dependencies {
 		classpath 'org.springframework.build.gradle:propdeps-plugin:0.0.7'
-		classpath 'io.spring.gradle:spring-io-plugin:0.0.4.RELEASE'
-		classpath 'org.asciidoctor:asciidoctor-gradle-plugin:1.5.3'
+		classpath 'io.spring.gradle:spring-io-plugin:0.0.8.RELEASE'
+		classpath 'org.asciidoctor:asciidoctor-gradle-plugin:1.5.12'
+		classpath 'io.spring.nohttp:nohttp-gradle:0.0.1.RELEASE'
 	}
 }
 
@@ -58,6 +59,12 @@ ext {
 	] as String[]
 }
 
+apply plugin: 'io.spring.nohttp'
+
+checkstyle {
+	toolVersion = 8.16
+}
+
 subprojects {
 	apply plugin: 'java'
 	apply plugin: 'maven'
@@ -129,7 +136,8 @@ subprojects {
 	}
 
 	repositories {
-		maven { url "https://repo.spring.io/libs-milestone" }
+		mavenCentral()
+		maven { url "https://repo.spring.io/libs-release" }
 	}
 }
 
@@ -196,6 +204,10 @@ configure(rootProject) {
 		archives docsZip
 		archives schemaZip
 	}
+
+	repositories {
+		mavenCentral()
+	}
 }
 
 ext {
@@ -253,7 +265,3 @@ task dist(dependsOn: assemble) {
 	group = 'Distribution'
 	description = 'Builds -dist, -docs and -schema distribution archives.'
 }
-
-task wrapper(type: Wrapper) {
-	gradleVersion = '2.10'
-}

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,5 @@
-#Thu Oct 26 14:15:54 CDT 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-bin.zip