Add Styles that Reflect the Validity of redux-form Fields

We are going to add styling to a redux-form Field that reflect its state. For example, if a field is invalid, it will have a red background, and if it’s valid, it will show a green tick next to the field. We are going to look at how to use a Field’s meta information for fine-tuning of under what exact circumstances such feedback shows, based on how the user has interacted with the Field.