Convert jshint to eslint

[GedasGa]

Motivation and Context

Resolves #141

Description

More info: apache/cordova#123

Testing

npm test

Checklist

• I've run the tests to see all new and existing tests pass
• ~~ I added automated test coverage as appropriate for this change ~~
• ~~ Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android)) ~~
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• ~~ I've updated the documentation if necessary~~

[janpio]

Any specific reason why move this to a new file instead of keeping it in the tests.js?

[GedasGa]

I was doing for the consistency across other repositories. For example, iOS, Android, Electron has a separate file. As well, it's a good idea to keep configurations global in a separate file, rather than inside a specific test file. Because otherwise, that would mean you would have to go to each test file and add it manually.

[janpio]

Plugin tests only have one test file, all the existing eslint setups of the other core plugins have it in the tests.js directly, I would greatly prefer to follow the same model to keep the plugin tests as simple as possible.

[GedasGa]

I still believe it should be in a separate file. This does not add complexity to the tests. It just keeps the configuration in a separate file. And generally, we try to do that as much as possible. Otherwise, we could also to have an eslint config entirely in the package.json file.

I would like to hear other's opinion on this.

[breautek]

@erisu has been working on building a eslint config module so that we can have a shared ruleset across all of our repos and when that is ready I think the eslint config file will be required to apply third-party configs.

But for the time being, I agree with janpio, we should try to keep things as consistent as possible, even though personally I would prefer eslint configs to be inside a .eslintrc.js file, I feel consistency is often more important when we are talking about something trivial/non-breaking.