Merge pull request #15 from 0x0c/master

Fix the issue that could not compile SDWebImageWebPCoder when using CocoaPods with use_modular_header!

Author: dreampiggy

SDWebImageWebPCoder/Classes/SDImageWebPCoder.h

@@ -7,7 +7,7 @@
  */
 
 #import <Foundation/Foundation.h>
-#import <SDWebImage/SDImageCoder.h>
+@import SDWebImage;
 
 /**
  Built in coder that supports WebP and animated WebP

SDWebImageWebPCoder/Classes/UIImage+WebP.h

@@ -6,7 +6,7 @@
  * file that was distributed with this source code.
  */
 
-#import <SDWebImage/SDWebImageCompat.h>
+@import SDWebImage;
 
 // This category is just use as a convenience method. For more detail control, use methods in `UIImage+MultiFormat.h` or directlly use `SDImageCoder`
 @interface UIImage (WebP)