Clear floats in .form__row. Apply error state to .form__input-container.
Ensure input field in .form__input-container fills full width when in error state

@asmega @gjvis Will the Rails field_with_errors div still be outputted
once the validation stuff goes live?
Add Rails form helper resets
Add csslint ignore for .error_message !important
Add TODO to rails_reset
Merge pull request #69 from moneyadviceservice/form-item-fixes

Clear floats in .form__row. Apply error state to .form__input-container.