bugfix, in Class Graphics, the method generateTexture should return type RenderTexture, but not current Texture. When use typescript to compile, there is a Error: Type 'Texture' is not assignable to type 'RenderTexture'.

Author: pigeonT

typescript/pixi.d.ts

@@ -637,7 +637,7 @@ declare module PIXI {
         drawShape(shape: Ellipse): GraphicsData;
         drawShape(shape: Polygon): GraphicsData;
         endFill(): Graphics;
-        generateTexture(resolution?: number, scaleMode?: number, padding?: number): Texture;
+        generateTexture(resolution?: number, scaleMode?: number, padding?: number): RenderTexture;
         lineStyle(lineWidth?: number, color?: number, alpha?: number): Graphics;
         lineTo(x: number, y: number): Graphics;
         moveTo(x: number, y: number): Graphics;
@@ -1883,4 +1883,4 @@ declare function requestAnimFrame(callback: Function): void;
 
 declare module PIXI.PolyK {
     export function Triangulate(p: number[]): number[];
-}
+}