0.5.3
 - enh: add std and median metrics (#19)
 - docs: make docs build on Windows
0.5.2
 - enh: clarify roi argument for Refocus.autofocus method (#17)
0.5.1
 - fix: internally normalize focusing distance to the wavelength for
   autofocusing with lmfit, because the scale seemed to affect the
   minimizer convergence (#14)
0.5.0
 - BREAKING CHANGE: The "legacy" minimizer is deprecated in favor of
   the new lmfit-based minimizer. The default minimizer is now "lmfit".
 - BREAKING CHANGE: Removed the "ret_grad" and "ret_d" keyword argument
   from autofocusing methods; there is now "ret_grid" and "ret_field"
   instead
 - BREAKING CHANGE: By default, the minimizers do not anymore return the
   refocused field, this can be re-enabled by using the `ret_field`
   option
 - build: lmfit is now a dependency
 - fix: check for None instead of boolean evaluation for
   metrics dealing with ROIs
0.4.3
 - ref: deprecate minimizer argument
 - ref: legacy minimizer now thinks in SI units
 - ref: minor cleanup in autofocusing code
0.4.2
 - docs: minor improvements
0.4.1
 - fix: `autofocus` method of Refocus was not functional
 - ref: use `Refocus.autofocus` for legacy autofocus method
 - docs: fix rtd builds
0.4.0
 - feat: implement nrefocus.RefocusPyFFTW for faster refocusing
   using pyfftw (#11)
 - enh: speed-up propagation kernel computation using numexpr
 - docs: cleanup
0.3.1
 - dist: include submodules in wheel/dist
0.3.0
 - feat: introduce nrefocus.RefocusNumpy and nrefocus.RefocusNumpy1D
   interface class for user-convenience and efficiency
 - docs: cleanup
 - ref: new submodule for metrics and metrics now accept a Refocus
   instance as an argument
 - ref: new submodule for minimizers and minimizers now accept
   a Refocus instance
 - ref: make legacy autofocusing code use the new Refocus class
0.2.1
 - fix: fix several minor bugs (deprecations?) that caused the
   tests to faile
 - ci: migrate to GitHub Actions
 - setup: setup.py test is deprecated
 - docs: refurbish documentation
0.2.0
 - Drop support for Python 2 (#8)
 - Code cleanup
0.1.8
 - Include docs in sdist
0.1.7
 - Update documentation and examples
0.1.6
 - Move documentation from GitHub to readthedocs.io
 - Add universal wheel on PyPI
 - Update tests on travis with new versions of NumPy
0.1.5
 - Code cleanup
0.1.4
 - Padding is now available in all methods (#2)
 - Added new convenient submodule `pad`
 - Bugfix: autofocusing did not return the correct focusing distance.
   This resulted in a slight offset in the refocusing distance for
   the method `autofocus_stack` when `same_dist=True` was set.
 - New test functions for `pad`
