update structure & remove images

SPPermission.podspec

@@ -92,8 +92,8 @@ Pod::Spec.new do |s|
   #  Not including the public_header_files will make all headers public.
   #
 
-  s.source_files  = "sources/sparrow/**/*.swift"
-  s.exclude_files = "sources/sparrow/**/*.plist"
+  s.source_files  = "source/sparrow/**/*.swift"
+  s.exclude_files = "source/sparrow/**/*.plist"
 
   # s.public_header_files = "Classes/**/*.h"