Fix typo from optins to options
Fix typo from optins to options

https://github.com/databricks/spark-csv/issues/209

In this PR, I fixed the typo.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #210 from HyukjinKwon/readme-typo.

databricks/spark-csv,falaki/spark-csv,abridgett/spark-csv,abridgett/spark-csv,databricks/spark-csv,falaki/spark-csv,databricks/spark-csv,falaki/spark-csv,abridgett/spark-csv