Expose `compose` method

from #194

This makes including multiple graphql HOCs on a single component much easier. It uses the compose method from recompose.

// component
const Template = (props) => (<div></div>);

// old
import { graphql } from 'react-apollo';

const withPeople = graphql(peopleQuery, { name: 'people' });
const withShips = graphql(shipsQuery, { name: 'ships' });

const ContainerWithData = withPeople(withShips(Template));

// new
import { compose, graphql } from 'react-apollo';

const ContainerWithData = compose(
  graphql(peopleQuery, { name: 'people' }),
  graphql(shipsQuery, { name: 'ships' })
)(Template);