Bump junit from 4.12 to 4.13.2

Bumps [junit](https://github.com/junit-team/junit4) from 4.12 to 4.13.2.
- [Release notes](https://github.com/junit-team/junit4/releases)
- [Changelog](https://github.com/junit-team/junit4/blob/main/doc/ReleaseNotes4.12.md)
- [Commits](junit-team/junit4@r4.12...r4.13.2)

---
updated-dependencies:
- dependency-name: junit:junit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

build.gradle

@@ -38,7 +38,7 @@ dependencies {
 
   compile 'com.googlecode.libphonenumber:libphonenumber:7.4.3'
 
-  testCompile 'junit:junit:4.12'
+  testCompile 'junit:junit:4.13.2'
   testCompile 'org.mockito:mockito-all:1.9.5'
   testCompile 'org.hamcrest:hamcrest-library:1.3'
 }