Bump lombok from 1.18.18 to 1.18.20 in /core

Bumps [lombok](https://github.com/rzwitserloot/lombok) from 1.18.18 to 1.18.20.
- [Release notes](https://github.com/rzwitserloot/lombok/releases)
- [Changelog](https://github.com/rzwitserloot/lombok/blob/master/doc/changelog.markdown)
- [Commits](https://github.com/rzwitserloot/lombok/compare/v1.18.18...v1.18.20)

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

Closes #171

Change-Id: I4825f6df2c4463be3e7f9ffed76bdf75fc592158
diff --git a/core/pom.xml b/core/pom.xml
index eddde87..372fa0a 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -241,7 +241,7 @@
 		<dependency>
 			<groupId>org.projectlombok</groupId>
 			<artifactId>lombok</artifactId>
-			<version>1.18.18</version>
+			<version>1.18.20</version>
 		</dependency>
 		<dependency>
 			<groupId>joda-time</groupId>