Breaking Changes
- Remove magics ([269](https://github.com/fastai/nbdev/issues/269))
- Removed callbacks ([253](https://github.com/fastai/nbdev/pull/253)), thanks to [pete88b](https://github.com/pete88b)
- move conda packager to `fastrelease` ([252](https://github.com/fastai/nbdev/issues/252))
New Features
- Place source code below heading on exports ([265](https://github.com/fastai/nbdev/pull/265)), thanks to [hamelsmu](https://github.com/hamelsmu)
- always skip cells labeled "skip" in test ([257](https://github.com/fastai/nbdev/issues/257))