Bump joda-time from 2.9.9 to 2.10.6 in /core

Bumps [joda-time](https://github.com/JodaOrg/joda-time) from 2.9.9 to 2.10.6.
- [Release notes](https://github.com/JodaOrg/joda-time/releases)
- [Changelog](https://github.com/JodaOrg/joda-time/blob/master/RELEASE-NOTES.txt)
- [Commits](https://github.com/JodaOrg/joda-time/compare/v2.9.9...v2.10.6)

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

Closes #90

Change-Id: I5a7908bc5beb2442ce99c4ecf53e39ace8ed68d7
diff --git a/core/pom.xml b/core/pom.xml
index 69cc0e0..c70334a 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -236,7 +236,7 @@
 		<dependency>
 			<groupId>joda-time</groupId>
 			<artifactId>joda-time</artifactId>
-			<version>2.9.9</version>
+			<version>2.10.6</version>
 		</dependency>
 		<dependency>
 			<groupId>de.ids_mannheim.korap</groupId>