Cleaner error handling for storiesOf
Cleaner error handling for storiesOf

Our entire storybook was broken because of a simple error, we provided `undefined` as the first parameter of `storiesOf`.
This was pretty hard to track down as it only results in issues later on during the runtime where storybook tries to manipulate the names that were given to the stories.
rhalff/storybook,rhalff/storybook,jribeiro/storybook,bigassdragon/storybook,storybooks/react-storybook,enjoylife/storybook,storybooks/react-storybook,rhalff/storybook,nfl/react-storybook,shilman/storybook,rhalff/storybook,storybooks/storybook,storybooks/storybook,rhalff/storybook,storybooks/react-storybook,jribeiro/storybook,kadirahq/react-storybook,bigassdragon/storybook,kadirahq/react-storybook,nfl/react-storybook,nfl/react-storybook,shilman/storybook,rhalff/storybook,jribeiro/storybook,shilman/storybook,shilman/storybook,bigassdragon/storybook,storybooks/storybook,storybooks/storybook,storybooks/storybook,storybooks/react-storybook,storybooks/storybook,storybooks/storybook,nfl/react-storybook,enjoylife/storybook,enjoylife/storybook,jribeiro/storybook,bigassdragon/storybook,enjoylife/storybook