GitLab

* Enable doctests in CI with xdoctest

* use xdoctest in travis file

* Fix doctest warnings

* dont test eggs directory

* Ensure xdoctest is installed before running CI

* add reduction_override flag

* change default value of reduction_override as None

* add assertion, fix format

* delete redudant statement in util

* delete redudant comment

* refactoring for losses

* update configs for guided anchoring

* add all imported losses to __all__

* allow weight=None for binary_cross_entropy

* use losses in mmdetection for FCOSHead

* bug fix for weight_reduce_loss

* add eps to iou_loss and handle weight=None

* unify loss api in FCOSHead

* fix avg_factor