message: Allows fontFamily to be configured
diff: import { css } from 'styled-components';
  -import { fontSize, space, borderColor, borders, color, width } from 'styled-system';
  +import { fontSize, fontFamily, space, borderColor, borders, color, width } from 'styled-system';
  import { preset } from 'react/styles/functions';
  import { antialiased } from 'react/styles/mixins';
  @@ -37,7 +37,7 @@ export const defaultMixin = css`
  display: block;
  background-color: white;
  line-height: ${LINE_HEIGHTS.input};
  - font-family: ${props => props.theme.fonts.sans};
  + ${preset(fontFamily, { font: 'sans' })}
  ${preset(width, { width: '100%' })}
  ${preset(color, { color: 'black' })}
  ${preset(fontSize, { f: 4 })}
  