common.gradle: update JUnit to v4.13.2

common.gradle

@@ -39,7 +39,7 @@ repositories {
 
 dependencies {
     // Adding dependencies here will add the dependencies to each subproject.
-    testCompile group: 'junit', name: 'junit', version: '4.12'
+    testCompile 'junit:junit:4.13.2'
     testCompile group: 'org.mockito', name: 'mockito-core', version: '3.0.0'
     testCompile group: 'org.easytesting', name: 'fest-assert-core', version: '2.0M10'
     testCompile 'org.codehaus.groovy:groovy-all:3.0.7'