Update react-apollo in / from 2.0.1 to 2.4.1

[dependencies]

Dependencies.io has updated react-apollo (a npm dependency in /) from "2.0.1" to "2.4.1".

2.4.1

Improvements

• Adds a onSubscriptionComplete prop to the Subscription component, that
  can be passed a callback to be called when the subscription observable
  is completed.
  
  sujeetsr in #2716

• During server-side rendering, ObservableQuery objects created in
  previous rendering passes will now be preserved in later passes (within
  the same getDataFromTree or getMarkupFromTree call), so that errors
  can be handled properly when using the errorPolicy: "all" option.
  
  PR #2753