Bump slf4j-api from 1.7.30 to 1.7.31 in /core

Bumps [slf4j-api](https://github.com/qos-ch/slf4j) from 1.7.30 to 1.7.31.
- [Release notes](https://github.com/qos-ch/slf4j/releases)
- [Commits](https://github.com/qos-ch/slf4j/commits)

Change-Id: I10e95a0abf87e787801666c34ee68eda6c5f444f

---
updated-dependencies:
- dependency-name: org.slf4j:slf4j-api
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Closes #207

Change-Id: I4bc2fdaa8fbb8e6c93d8bc308d3d6cd35f41216c
diff --git a/core/pom.xml b/core/pom.xml
index 9638943..988877d 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -221,7 +221,7 @@
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-api</artifactId>
-			<version>1.7.30</version>
+			<version>1.7.31</version>
 		</dependency>
 		
 		<!-- Java Assist -->