Fix jacoco build error

Issue gh-95

config/spring-security-config2.gradle

@@ -1,13 +1,12 @@
 apply plugin: 'io.spring.convention.spring-module'
 
 dependencies {
+	compile project(':spring-security-oauth2-authorization-server')
 	compile 'org.springframework.security:spring-security-core'
 	compile 'org.springframework.security:spring-security-config'
 	compile springCoreDependency
 
-	optional project(':spring-security-oauth2-authorization-server')
+	testCompile project(path: ':spring-security-oauth2-authorization-server', configuration: 'tests')
-	optional project(path: ':spring-security-oauth2-authorization-server', configuration: 'tests')
-
 	testCompile 'org.springframework.security:spring-security-test'
 	testCompile 'junit:junit'
 	testCompile 'org.assertj:assertj-core'
@@ -16,3 +15,7 @@ dependencies {
 
 	provided 'javax.servlet:javax.servlet-api'
 }
+
+jacoco {
+	toolVersion = '0.8.5'
+}

oauth2-authorization-server/spring-security-oauth2-authorization-server.gradle

@@ -15,3 +15,7 @@ dependencies {
 
 	provided 'javax.servlet:javax.servlet-api'
 }
+
+jacoco {
+	toolVersion = '0.8.5'
+}