Upgrade to Mockito 2.19.0

Author: sbrannen

gradle.properties

@@ -24,7 +24,7 @@ degraphVersion      = 0.1.4
 jmhVersion          = 1.21
 junit4Version       = 4.12
 log4jVersion        = 2.11.0
-mockitoVersion      = 2.18.3
+mockitoVersion      = 2.19.0
 ota4jVersion        = 1.1.0
 surefireVersion     = 2.21.0