Only the Sentry hook uses the values of the passed context. Therefore, we removed the values from our log statements when we shifted them from an extra `WithField` call to the context.
We fix this behavior by introducing a Logrus Hook that copies a fixed set of context values to the logging data.
We previously didn't really had any structure in our project apart
from creating a new folder for each package in our project root.
Now that we have accumulated some packages, we use the well-known
Golang project layout in order to clearly communicate our intent
with packages. See https://github.com/golang-standards/project-layout
