Reformat BUCK files

Summary: Reformat BUCK files to better conform with style.

Reviewed By: zertosh

Differential Revision: D5901515

fbshipit-source-id: 93e8c56450f65b691af9017d880e6cf2a2cdb7af

YogaKit/BUCK

@@ -30,8 +30,8 @@ COMPILER_FLAGS = [
 apple_library(
     name = "YogaKit",
     srcs = glob(["Source/**/*.m"]),
-    compiler_flags = COMPILER_FLAGS,
     exported_headers = glob(["Source/**/*.h"]),
+    compiler_flags = COMPILER_FLAGS,
     frameworks = [
         "$SDKROOT/System/Library/Frameworks/Foundation.framework",
         "$SDKROOT/System/Library/Frameworks/UIKit.framework",