Fix dependencies in pom.xml

- Use Gerrit API version 2.15.7
- Remove unnecessary (and outdated) dependencies on Jgit and SSHD
- Update maven-compiler-plugin to latest version

Change-Id: Ie614f91da8e274c7bc089ac6c81856f65d736021

pom.xml

diff --git a/pom.xml b/pom.xml
index 4c7f0e4..fecdcb7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -22,7 +22,7 @@
   <groupId>com.googlesource.gerrit.plugins.batch</groupId>
   <artifactId>batch</artifactId>
   <packaging>jar</packaging>
-  <version>2.15</version>
+  <version>2.15.7</version>
   <name>batch</name>
 
   <properties>
@@ -59,7 +59,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-compiler-plugin</artifactId>
-        <version>2.3.2</version>
+        <version>3.8.0</version>
         <configuration>
           <source>1.8</source>
           <target>1.8</target>
@@ -76,18 +76,6 @@
       <version>${Gerrit-ApiVersion}</version>
       <scope>provided</scope>
     </dependency>
-
-    <dependency>
-      <groupId>org.eclipse.jgit</groupId>
-      <artifactId>org.eclipse.jgit</artifactId>
-      <version>3.4.1.201406201815-r</version>
-    </dependency>
-
-    <dependency>
-      <groupId>org.apache.sshd</groupId>
-      <artifactId>sshd-core</artifactId>
-      <version>0.14.0</version>
-    </dependency>
   </dependencies>
 
   <repositories>
@@ -96,4 +84,4 @@
       <url>https://gerrit-api.commondatastorage.googleapis.com/release/</url>
     </repository>
   </repositories>
-</project>
\ No newline at end of file
+</project>