The probe package is no longer available in the Minio server
repo. This change just moves probe from the vendor directory to its
own dir under `pkg`.
This is a maintenance fix.
This patch adds UTCNow() function which returns current UTC time.
This is equivalent of UTCNow() == time.Now().UTC()
Refer https://github.com/minio/minio/pull/3931
This fixes#1889.
```sh
mc mirror -w
```
Now runs continous even when the source is not available.
Reconnects indefinitely in a binomially increasing fashion
and also allows jitter so that the retry has a nice
distribution as well.
This allows for 'mc mirror -w' to run continously without
further monitoring.
