Using Spring was hiding an loading error. When you start Rspec, Rails
and its engines are not loaded yet. So our way to load the spec helper
via `Rails.root` did not work when you ran specs on their own without
loading Rails with Spring first.
We wanted to use our own context before but now I found a better way for
the connector to cache the context and therfore we can use the original
implementation again.
This protects us from the DFC website going down or the DFC updating
the context with breaking changes. We are in control of updating the
context now (opt-in to newer versions).
