Bala FA 60f52f461f add network read performance collection support. (#8038)
ReST API on /minio/admin/v1/performance?perfType=net[?size=N] 
returns

```
{
  "PEER-1": [
             {
	       "addr": ADDR,
	       "readPerf": DURATION,
	       "error": ERROR,
	     },
	     ...
	   ],
  ...
  ...
  "PEER-N": [
             {
	       "addr": ADDR,
	       "readPerf": DURATION,
	       "error": ERROR,
	     },
	     ...
	   ]
}
```
2019-08-19 08:26:32 +05:30
..
2019-08-02 14:25:00 -07:00
2019-07-13 00:29:44 +01:00
2019-08-02 14:25:00 -07:00
2019-04-17 09:52:08 -07:00