Support New "Job Hook" Hook Renaming (#131)

* fix #130 support new hook name
* rename BuildEvent consts to be more descriptive

Author: armsnyder

src/main/java/org/gitlab4j/api/webhook/BuildEvent.java

@@ -10,7 +10,10 @@
 @XmlAccessorType(XmlAccessType.FIELD)
 public class BuildEvent implements Event {
 
-    public static final String X_GITLAB_EVENT = "Build Hook";
+    /** X-Gitlab-Event header value pre GitLab v9.3.0 */
+    public static final String BUILD_HOOK_X_GITLAB_EVENT = "Build Hook";
+    /** X-Gitlab-Event header value post GitLab v9.3.0 */
+    public static final String JOB_HOOK_X_GITLAB_EVENT = "Job Hook";
     public static final String OBJECT_KIND = "build";
 
     private String ref;

src/main/java/org/gitlab4j/api/webhook/WebHookManager.java

@@ -61,7 +61,8 @@ public void handleEvent(HttpServletRequest request) throws GitLabApiException {
         LOG.info("handleEvent: X-Gitlab-Event=" + eventName);
         switch (eventName) {
 
-        case BuildEvent.X_GITLAB_EVENT:
+        case BuildEvent.BUILD_HOOK_X_GITLAB_EVENT:
+        case BuildEvent.JOB_HOOK_X_GITLAB_EVENT:
         case IssueEvent.X_GITLAB_EVENT:
         case MergeRequestEvent.X_GITLAB_EVENT:
         case NoteEvent.X_GITLAB_EVENT: