Update mockito-core to 2.23.4
Update mockito-core to 2.23.4

ChristopherDavenport/http4s,ChristopherDavenport/http4s,aeons/http4s,rossabaker/http4s,aeons/http4s,http4s/http4s,rossabaker/http4s,aeons/http4s,ChristopherDavenport/http4s