Bump junit from 4.12 to 4.13.1

Bumps [junit](https://github.com/junit-team/junit4) from 4.12 to 4.13.1.
- [Release notes](https://github.com/junit-team/junit4/releases)
- [Changelog](https://github.com/junit-team/junit4/blob/main/doc/ReleaseNotes4.12.md)
- [Commits](junit-team/junit4@r4.12...r4.13.1)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -13,7 +13,7 @@
         <elasticsearch.version>1.7.0</elasticsearch.version>
         <jackson.version>2.8.1</jackson.version>
         <spring.version>4.3.2.RELEASE</spring.version>
-        <junit.version>4.12</junit.version>
+        <junit.version>4.13.1</junit.version>
 
         <java.version>1.8</java.version>
         <maven.compiler.version>2.3.2</maven.compiler.version>