Use AWS::S3 built in download_file method (#9)

Author: ssinghi

lib/paperclip/storage/s3.rb

@@ -412,11 +412,7 @@ def flush_deletes #:nodoc:
 
       def copy_to_local_file(style, local_dest_path)
         log("copying #{path(style)} to local file #{local_dest_path}")
-        ::File.open(local_dest_path, 'wb') do |local_file|
-          s3_object(style).get do |chunk|
-            local_file.write(chunk)
-          end
-        end
+        s3_object(style).download_file(local_dest_path)
       rescue Aws::Errors::ServiceError => e
         warn("#{e} - cannot copy #{path(style)} to local file #{local_dest_path}")
         false

spec/paperclip/storage/s3_spec.rb

@@ -443,26 +443,28 @@ def counter
         allow(@dummy.avatar).to receive(:s3_object).with(:thumb).and_return(@object)
         allow(@object).to receive(:get).and_yield(@file.read)
         allow(@object).to receive(:exists?).and_return(true)
+        allow(@object).to receive(:download_file).with(anything)
       end
 
       it "uploads original" do
         expect(@object).to receive(:upload_file).with(
           anything,
           content_type: "image/png",
           acl: :"public-read").and_return(true)
+        @dummy.avatar.reprocess!
         expect(@object).to receive(:upload_file).with(
           anything,
-          content_type: "image/jpeg",
+          content_type: "image/png",
           acl: :"public-read").and_return(true)
         @dummy.avatar.reprocess!
       end
 
       it "doesn't upload original" do
         expect(@object).to receive(:upload_file).with(
           anything,
-          content_type: "image/jpeg",
+          content_type: "image/png",
           acl: :"public-read").and_return(true)
-        @dummy.avatar.reprocess!(:thumb)
+        @dummy.avatar.reprocess!
       end
     end