test(deps): update dependency junit:junit to v4 (#272)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [junit:junit](http://junit.org) ([source](https://togithub.com/junit-team/junit4)) | major | `1.0.5-SNAPSHOT` -> `4.13.1` |

---

### Renovate configuration

:date: **Schedule**: At any time (no schedule defined).

:vertical_traffic_light: **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

:recycle: **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

:no_bell: **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#github/googleapis/java-recaptchaenterprise).

Author: renovate-bot

recaptcha_enterprise/pom.xml

@@ -42,8 +42,7 @@
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-recaptchaenterprise</artifactId>
     </dependency>
-    <!-- [END recaptchaenterprise_install_with_bom] -->
-
+    <!-- [START_EXCLUDE] -->
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
@@ -56,5 +55,7 @@
       <version>1.1</version>
       <scope>test</scope>
     </dependency>
+    <!-- [END_EXCLUDE] -->
   </dependencies>
+  <!-- [END recaptchaenterprise_install_with_bom] -->
 </project>