Bugfixes on refactored code.

- Removed hard coded "column-chart" argument.
- Defaulting config to an empty object.
- Throwing an error if no argument is passed to setData()
- Renaming config function to setConfig() to avoid naming conflict with instance variable of Dataviz.
Don't need to specify null, undefined works fine.
Moving setCapabilities into data setting section, as it techncially relies on the data and not the config being passed in.
Check for spinner before trying to stop it.
Move setting of default chart type

Set default chart type after calling setData() rather than setConfig(), as it technically relies on the data and not the config. Good to be able to get what the default type is after setting data so you can make decisions before setting the config.