Add additional job scope (#1294)

Author: LeJeanbono

gitlab4j-models/src/main/java/org/gitlab4j/models/Constants.java

@@ -442,6 +442,9 @@ public enum JobScope {
         FAILED,
         SUCCESS,
         CANCELED,
+        CANCELING,
+        PREPARING,
+        SCHEDULED,
         SKIPPED,
         MANUAL,
         WAITING_FOR_RESOURCE;