Update dependencies, enable pruning for vendor/

So, `dep` got an nice new feature to remove tests and non-go files from
`vendor/`, and this brings the size of the vendor directory from ~300MiB
down to ~20MiB. We don that now.

vendor/github.com/minio/minio-go/api-put-object-copy.go

@@ -1,6 +1,6 @@
 /*
  * Minio Go Library for Amazon S3 Compatible Cloud Storage
- * Copyright 2017 Minio, Inc.
+ * Copyright 2017, 2018 Minio, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,67 @@
 
 package minio
 
+import (
+	"context"
+	"io"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/minio/minio-go/pkg/encrypt"
+)
+
 // CopyObject - copy a source object into a new object
 func (c Client) CopyObject(dst DestinationInfo, src SourceInfo) error {
-	return c.ComposeObject(dst, []SourceInfo{src})
+	return c.CopyObjectWithProgress(dst, src, nil)
+}
+
+// CopyObjectWithProgress - copy a source object into a new object, optionally takes
+// progress bar input to notify current progress.
+func (c Client) CopyObjectWithProgress(dst DestinationInfo, src SourceInfo, progress io.Reader) error {
+	header := make(http.Header)
+	for k, v := range src.Headers {
+		header[k] = v
+	}
+
+	var err error
+	var size int64
+	// If progress bar is specified, size should be requested as well initiate a StatObject request.
+	if progress != nil {
+		size, _, _, err = src.getProps(c)
+		if err != nil {
+			return err
+		}
+	}
+
+	if src.encryption != nil {
+		encrypt.SSECopy(src.encryption).Marshal(header)
+	}
+
+	if dst.encryption != nil {
+		dst.encryption.Marshal(header)
+	}
+	for k, v := range dst.getUserMetaHeadersMap(true) {
+		header.Set(k, v)
+	}
+
+	resp, err := c.executeMethod(context.Background(), "PUT", requestMetadata{
+		bucketName:   dst.bucket,
+		objectName:   dst.object,
+		customHeader: header,
+	})
+	if err != nil {
+		return err
+	}
+	defer closeResponse(resp)
+
+	if resp.StatusCode != http.StatusOK {
+		return httpRespToErrorResponse(resp, dst.bucket, dst.object)
+	}
+
+	// Update the progress properly after successful copy.
+	if progress != nil {
+		io.CopyN(ioutil.Discard, progress, size)
+	}
+
+	return nil
 }