Major restructuring/cleanup

- Renamed `GenericDetectors` -> `detectors`
- Removed `ConceptDetectors`. Full concepts should live outside of this
 repository. The  only full detector concepts should be within the
 context of `examples`.
- New version number 0.4.0
2 jobs for v0.4.0 in 1 minute and 41 seconds
Name Stage Failure
docker_tag Container
docker rmi
publish latest to
docker tag npdet:latest
Error parsing reference: "" is not a valid repository/tag: invalid reference format
make: *** [Makefile:100: publish-version] Error 1
Cleaning up file based variables
ERROR: Job failed: exit code 1