Bump mockito-core from 2.20.1 to 2.21.0

Bumps [mockito-core](https://github.com/mockito/mockito) from 2.20.1 to 2.21.0.
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](mockito/mockito@v2.20.1...v2.21.0)

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

pom.xml

@@ -182,7 +182,7 @@
             <dependency>
                 <groupId>org.mockito</groupId>
                 <artifactId>mockito-core</artifactId>
-                <version>2.20.1</version>
+                <version>2.21.0</version>
                 <scope>test</scope>
             </dependency>
             <dependency>