Bump assertj-core from 3.8.0 to 3.20.1

Bumps [assertj-core](https://github.com/assertj/assertj-core) from 3.8.0 to 3.20.1.
- [Release notes](https://github.com/assertj/assertj-core/releases)
- [Commits](assertj/assertj@assertj-core-3.8.0...assertj-core-3.20.1)

---
updated-dependencies:
- dependency-name: org.assertj:assertj-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pom.xml

@@ -119,7 +119,7 @@
         <hamcrest.version>1.3</hamcrest.version>
         <mockito.version>1.10.19</mockito.version>
         <mockito2.version>2.28.2</mockito2.version>
-        <assertj.version>3.8.0</assertj.version>
+        <assertj.version>3.20.1</assertj.version>
         <guava.version>29.0-jre</guava.version>
         <jimfs.version>1.1</jimfs.version>
         <testng.version>7.1.0</testng.version> <!-- TCK Tests -->