Bump junit from 4.11 to 4.13

Bumps [junit](https://github.com/junit-team/junit4) from 4.11 to 4.13.
- [Release notes](https://github.com/junit-team/junit4/releases)
- [Changelog](https://github.com/junit-team/junit4/blob/master/doc/ReleaseNotes4.11.md)
- [Commits](junit-team/junit4@r4.11...r4.13)

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

Author: dependabot-preview[bot]

build.gradle

@@ -40,7 +40,7 @@ repositories {
 dependencies {
     compile 'rhino:js:1.6R5'
     compile 'antlr:antlr:2.7.6'
-    testCompile group: 'junit', name: 'junit', version: '4.11'
+    testCompile group: 'junit', name: 'junit', version: '4.13'
     antlr 'antlr:antlr:2.7.7'
 }