Added lock/unlock op and additional properties

Issue #355

src/main/java/org/kohsuke/github/GHIssue.java

@@ -68,6 +68,7 @@ public class GHIssue extends GHObject implements Reactable{
     protected GHIssue.PullRequest pull_request;
     protected GHMilestone milestone;
     protected GHUser closed_by;
+    protected boolean locked;
 
     /**
      * @deprecated use {@link GHLabel}
@@ -129,6 +130,10 @@ public String getTitle() {
         return title;
     }
 
+    public boolean isLocked() {
+        return locked;
+    }
+
     public GHIssueState getState() {
         return Enum.valueOf(GHIssueState.class, state.toUpperCase(Locale.ENGLISH));
     }
@@ -148,6 +153,14 @@ public URL getApiURL(){
         return GitHub.parseURL(url);
     }
 
+    public void lock() throws IOException {
+        new Requester(root).method("PUT").to(getApiRoute()+"/lock");
+    }
+
+    public void unlock() throws IOException {
+        new Requester(root).method("PUT").to(getApiRoute()+"/lock");
+    }
+
     /**
      * Updates the issue by adding a comment.
      *

src/main/java/org/kohsuke/github/GHPullRequest.java

@@ -50,8 +50,8 @@ public class GHPullRequest extends GHIssue {
 
     // details that are only available when obtained from ID
     private GHUser merged_by;
-    private int review_comments, additions;
-    private boolean merged;
+    private int review_comments, additions, commits;
+    private boolean merged, maintainer_can_modify;
     private Boolean mergeable;
     private int deletions;
     private String mergeable_state;
@@ -167,11 +167,21 @@ public int getAdditions() throws IOException {
         return additions;
     }
 
+    public int getCommits() throws IOException {
+        populate();
+        return commits;
+    }
+
     public boolean isMerged() throws IOException {
         populate();
         return merged;
     }
 
+    public boolean canMaintainerModify() throws IOException {
+        populate();
+        return maintainer_can_modify;
+    }
+
     public Boolean getMergeable() throws IOException {
         populate();
         return mergeable;