1.4.0rc4

First release in the 1.4.x series.
This release includes enhancements and bug-fixes towards the release of the first
beta version of *dMRIPrep*.
It also contains new features that are necessary for the API overhaul that has
happened within the new *SDCFlows 2.x* series.
The new series include a cross-cutting (modalities, species) workflow to generate
EPI references.
Finally other *NiPreps* will also have a first release with specific support for
them: *NiRodents* and *NiBabies* (and their corresponding *fMRIPrep* extensions).

A list of prominent changes follows:

* FIX: Address issues with ``RobustAverage`` global signal measurement (#607)
* FIX: ``NonsteadyStatesDetector`` wrongly using Nipype's ``is_outlier`` (#605)
* FIX: Change in *svgutils*' API on 0.3.2 breaks reportlets (#599)
* FIX: Check for ``in_segm`` input, not ``seg_file`` (typo) (#592)
* FIX: Use the mask to calculate FOV rather than the fixed image in ``GenerateSamplingReference`` (#583)
* FIX: Allow omission of ``<res>`` for template normalization (#582)
* FIX: Include ``_T2starw`` ``_MTw`` and ``_TSE``-suffixes in ``build_path`` options (#584)
* FIX: ``DerivativesDataSink`` warning when it has multiple source files (#573)
* ENH: Add an inversion operation to ``IntensityClip`` (#616)
* ENH: Cross-cutting (modalities, species) workflow to generate EPI references (#610)
* ENH: Add a ``RobustAverage`` interface and split volume selection (#602)
* ENH: Revise some patterns of the ``BIDSLayout`` config to aid *SDCFlows* new API (#585)
* ENH: Upstream *fMRIPrep*'s ``init_bbreg_wf`` to integrate it in *dMRIPrep* (#586)
* MAINT: Add DS030 dataset, with clipped (55 timepoints) BOLD data (#609)
* MAINT: Migrate ``ds003_downsampled`` to ``nipreps-data`` (#608)
* MAINT: Move mask-regressions test-data to datalad + nipreps-data (#606)
* MAINT: Refactor structure of interfaces (#603)
* MAINT: Drop Python 3.6, test setuptools builds, pip installations, and revise Docker pinned versions (#593)
* MAINT: CircleCI housekeeping (#580)