## What changes were proposed in this pull request?

https://issues.apache.org/jira/browse/SPARK-15148

Mainly it improves the performance roughtly about 30%-40% according to the [release note](https://github.com/uniVocity/univocity-parsers/releases/tag/v2.1.0). For the details of the purpose is described in the JIRA.

This PR upgrades Univocity library from 2.0.2 to 2.1.0.

## How was this patch tested?

Existing tests should cover this.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #12923 from HyukjinKwon/SPARK-15148.