Bump hibernate.version from 5.3.7.Final to 5.4.20.Final in /core

Bumps `hibernate.version` from 5.3.7.Final to 5.4.20.Final.

Updates `hibernate-ehcache` from 5.3.7.Final to 5.4.20.Final
- [Release notes](https://github.com/hibernate/hibernate-orm/releases)
- [Changelog](https://github.com/hibernate/hibernate-orm/blob/5.4.20/changelog.txt)
- [Commits](https://github.com/hibernate/hibernate-orm/compare/5.3.7...5.4.20)

Updates `hibernate-jpamodelgen` from 5.3.7.Final to 5.4.20.Final
- [Release notes](https://github.com/hibernate/hibernate-orm/releases)
- [Changelog](https://github.com/hibernate/hibernate-orm/blob/5.4.20/changelog.txt)
- [Commits](https://github.com/hibernate/hibernate-orm/compare/5.3.7...5.4.20)

Signed-off-by: dependabot[bot] <support@github.com>

Closes #100

Change-Id: Ide7f977b334df4aa485788f51ed5dccbc3dfbb6e
diff --git a/core/pom.xml b/core/pom.xml
index f8911f4..229fb65 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -11,7 +11,7 @@
 		<spring.version>5.2.9.RELEASE</spring.version>
 		<jersey.version>1.19.4</jersey.version>
 		<jetty.version>9.4.31.v20200723</jetty.version>
-		<hibernate.version>5.3.7.Final</hibernate.version>
+		<hibernate.version>5.4.20.Final</hibernate.version>
 		<log4j.version>2.13.3</log4j.version>
 	</properties>
 	<build>