add pr review id to prs.comment

Author: javoire

src/main/java/com/spotify/github/v3/prs/Comment.java

@@ -129,4 +129,8 @@ public interface Comment extends UpdateTracking {
   /** Node ID */
   @Nullable
   String nodeId();
+
+  /** Pull request review ID. */
+  @Nullable
+  Long pullRequestReviewId();
 }

src/test/java/com/spotify/github/v3/clients/PullRequestClientTest.java

@@ -371,5 +371,6 @@ public void testCreateCommentReply() throws Throwable {
     assertThat(comment.line(), is(2));
     assertThat(comment.originalLine(), is(2));
     assertThat(comment.side(), is("RIGHT"));
+    assertThat(comment.pullRequestReviewId(), is(42L));
   }
 }