adding eslint

[dbrudner]

I added eslint to the project. Here's a couple notes:

• Extends airbnb rules
• Set to use 2 space for indentation, per the pattern established in the project.
• Set to use single quotes. There wasn't consistency across the project, I selected single quotes. It's easy to revert to double quotes by changing the setting in .eslintrc.json and running eslint --fix.
• I changed files using jsx to have the extension .jsx instead of .js
• I ran eslint --fix and committed the changes made by that command.
• Instead of fixing the errors came up, I elected to ignore the rules inside .eslintrc.json. I did so because firstly, I don't know how the contributors wish to define these rules, and secondly, that potentially falls outside of the scope of the issue. There's some decisions that'll have to be made there, and I don't think I should be the person to make them.

I'd recommend moving forward that whoever's project this is make decisions about the linting rules, then remove/change the rules set in .eslintrc.json and fix the files so the code complies with the rules decided upon.

Having said that, thank you for letting me contribute. If you have any questions, comments, please let me know or comment directly in the PR and I can make changes before merging.

[gregorysl]

I'm curious, why

I changed files using jsx to have the extension .jsx instead of .js

[dbrudner]

@gregorysl It was caught by the linter and easy to change, so I made the change. JavaScript files containing jsx should contain that file extension. Feel free to revert if you'd like.

More on this here: airbnb/javascript#985

[dillionverma]

Thank you so much for the very thoughtful and lengthy PR.

I just looked through the lint and it looks very clean. Great work 🎉 💯

Looking more into it, I think it still might be better to keep the files named as .js as per here

Other than that, just fix the merge conflicts and I will merge this in 😄

[dillionverma]

Some merge conflicts remaining

[dbrudner]

Resolved the conflicts, looks good to go from my end! Comment away if there's something I missed. Other than that, I completely support the decision to keep using .js files and think there's definitely a good argument for doing so. I enjoyed contributing here and would be interested in tackling more issues in the future!

[dillionverma]

Thanks so much again for contributing! I think one small remaining issue is src/index.jsx.

Then it is ready to merge

[dbrudner]

Encountered a second error after fixing this, both should be fixed now

[dillionverma]

Merged it in, thanks again so much for your help!