Updated requirements, instructions typos and missing steps

Thank you for such a great example, I just wanted to add my two cents.

* Fixed reference to `SparkSqlDemo`, is at root package.
* No need to compile pre-build of connector.
* Fixed docs on `spark-submit` arguments
* Updated dependencies
* Updated typo in instructions, now using actual `dsetool sparkmaster` expanded in shell.
* `SparkSqlDemo` now connects to argument.