Manage specific version of htmlunit dependencies

This allows Spring Boot to resolve consistent versions

Fixes: gh-7888

Author: eleftherias

gradle/dependency-management.gradle

@@ -57,7 +57,7 @@ dependencies {
 		management "junit:junit:4.12"
 		management "ldapsdk:ldapsdk:4.+"
 		management "net.sf.ehcache:ehcache:2.+"
-		management "net.sourceforge.htmlunit:htmlunit:2.+"
+		management "net.sourceforge.htmlunit:htmlunit:2.37.0"
 		management "net.sourceforge.nekohtml:nekohtml:1.+"
 		management "nz.net.ultraq.thymeleaf:thymeleaf-layout-dialect:2.+"
 		management "opensymphony:sitemesh:2.+"
@@ -98,7 +98,7 @@ dependencies {
 		management "org.powermock:powermock-module-junit4:2.+"
 		management "org.powermock:powermock-reflect:2.+"
 		management "org.python:jython:2.5.+"
-		management "org.seleniumhq.selenium:htmlunit-driver:2.+"
+		management "org.seleniumhq.selenium:htmlunit-driver:2.37.0"
 		management "org.seleniumhq.selenium:selenium-java:3.+"
 		management "org.seleniumhq.selenium:selenium-support:3.+"
 		management "org.skyscreamer:jsonassert:1.+"