adding forceAtlas layout typings

sigmajs/sigmajs-tests.ts

@@ -53,4 +53,13 @@ module SigmaJsTests {
     sigma.parsers.gexf('myGraph.gexf', s, () => {
         s.refresh();
     });
+
+    s.configForceAtlas2({
+        worker: true
+    });
+
+    s.isForceAtlas2Running();
+    s.killForceAtlas2();
+    s.startForceAtlas2();
+    s.stopForceAtlas2();
 }

sigmajs/sigmajs.d.ts

@@ -96,6 +96,14 @@ declare module SigmaJs{
         kill(): void;
         refresh(): void;
         renderers: Renderer[];
+
+        // forceAtlas2 layout
+        configForceAtlas2(configs: { [key: string]: any }): void;
+        isForceAtlas2Running(): boolean;
+        killForceAtlas2(): void;
+        startForceAtlas2(): void;
+        startForceAtlas2(configs: { [key: string]: any }): void;
+        stopForceAtlas2(): void;
     }
 
     interface SigmaConfigs {