Bump junit from 4.12 to 4.13

Bumps [junit](https://github.com/junit-team/junit4) from 4.12 to 4.13.
- [Release notes](https://github.com/junit-team/junit4/releases)
- [Changelog](https://github.com/junit-team/junit4/blob/master/doc/ReleaseNotes4.12.md)
- [Commits](junit-team/junit4@r4.12...r4.13)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

build.gradle

@@ -43,7 +43,7 @@ ext {
 
     // Test Dependencies
     testRunnerRulesVersion = '1.0.2'
-    junitVersion = '4.12'
+    junitVersion = '4.13'
     espressoVersion = '3.0.2'
 
     // External Libraries