Update plugin to support Gerrit 2.15

Change-Id: I9fd750ea75d77e0416dd61963cca7fea8ce96076

pom.xml

diff --git a/pom.xml b/pom.xml
index 8e7626b..033a3d8 100644
--- a/pom.xml
+++ b/pom.xml
@@ -26,14 +26,14 @@
 
   <properties>
     <Gerrit-ApiType>plugin</Gerrit-ApiType>
-    <Gerrit-ApiVersion>2.14.1</Gerrit-ApiVersion>
+    <Gerrit-ApiVersion>2.15.2</Gerrit-ApiVersion>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <jaxb2-basics-runtime.version>0.6.4</jaxb2-basics-runtime.version>
     <jacoco.version>0.7.5.201505241946</jacoco.version>
     <gitdescribe-maven-plugin.version>3.0</gitdescribe-maven-plugin.version>
     <maven-jaxb2-plugin.version>0.7.0</maven-jaxb2-plugin.version>
     <truth.version>0.27</truth.version>
-    <jgit.junit.version>4.7.0.201704051617-r</jgit.junit.version>
+    <jgit.junit.version>4.9.0.201710071750-r</jgit.junit.version>
   </properties>
 
   <build>

src/main/resources/Documentation/about.md

diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
index f62b4a0..462e512 100644
--- a/src/main/resources/Documentation/about.md
+++ b/src/main/resources/Documentation/about.md
@@ -2,7 +2,7 @@
 and generate rev-specific manifests (similar to "repo manifest -o") and store
 them to a separate git repository (configurable.)
 
-> **Warning: this plugin is currently under development and is targeting 2.14.1**
+> **Warning: this plugin is currently under development and is targeting 2.15.2**
 
 The rev-specific manifest of each source manifest is stored in its own branch
 with the following naming convention: