The forecaster component should be located outside the docker directory

[ema-pe]

The source code for the forecaster component is currently located in docker/forecaster. This is not a preferred location, as the docker directory should only contain code related to the generation of docker images (such as static files or dockerfiles). The forecaster should be in an independent directory under the project root, or under the dfaasagent directory.

Stefano Cattaneo, the original author of this module, said that he placed the forecaster component there because we could not run Docker with two independent context paths (files and forecaster), so he solved this problem by having a single context under the docker directory.