DEV: added csv export to states

[Shivathanu]

Description:

Added CSV export option along with the chart display for additional visualization option.

Instructions:

The csv file generation is configured with the states feature. The output is a csv file with the data stored in output folder.

Run command:

corona --s states

Fixes #98

[milespossing]

this works, but the command you've provided doesn't seem to. If corona states were to be run it works perfectly and yields a csv.

[pokimochi]

corona states throws an error when the output folder does not exist. I suggest creating the directory if it doesn't exist before writing the records.

[kushagra-shukla]

Hi, I want to add code to remove this bug. How do I do this? Should I clone, make amends and then do a PR ? or something else ?

[Shivathanu]

i suggest you can clone and add a new commit to this pr with the fix, thanks

[yuntaeJ]

I solved that problem using directory checking process

 var fs=require('fs');

		if (!fs.existsSync('./output')){
			fs.mkdirSync('./output');
		}