Add trailing headers support

[klauspost]

Description

Add trailing headers to requests when specified in config.

Requires minio/minio-go#1705

How to test this PR?

Modify config:

		"mys3": {
			"url": "https://s3.amazonaws.com",
			"accessKey": "AKIA3WNQJCXE3JVMGFPN",
			"secretKey": xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
			"api": "s3v4",
			"path": "auto",
			"trailingHeaders":true
		},

Types of changes

• New feature (non-breaking change which adds functionality)

[vadmeste]

Few comments

[harshavardhana]

Will get this reviewed by @abperiasamy if we are okay to make changes to config.json with new fields. Sorry for the delay.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed after 21 days if no further activity occurs. Thank you for your contributions.

[harshavardhana]

Still valid needs discussion.

[harshavardhana]

Will discuss this with @abperiasamy next week and get this merged.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed after 21 days if no further activity occurs. Thank you for your contributions.