chore(deps): update dependency junit:junit to v4.13 (#27)

Author: renovate-bot

pom.xml

@@ -65,7 +65,7 @@
     <site.installationModule>google-cloud-storage-parent</site.installationModule>
     <google.core.version>1.91.3</google.core.version>
     <google.api-common.version>1.8.1</google.api-common.version>
-    <junit.version>4.12</junit.version>
+    <junit.version>4.13</junit.version>
     <threeten.version>1.4.0</threeten.version>
     <javax.annotations.version>1.3.2</javax.annotations.version>
     <animal-sniffer.version>1.18</animal-sniffer.version>