This blog helped fix the same problem for me:
Inside the dependencies for Mockito and Junit, the author added excludes:
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<exclusions>
<exclusion>
<artifactId>hamcrest-core</artifactId>
<groupId>org.hamcrest</groupId>
</exclusion>
</exclusions>
</dependency>