2.0.0rc3

* FIX: Convert SEI fieldmaps given in rad/s into Hz (#127)
* FIX: Limit ``3dQwarp`` to maximum 4 CPUs for stability reasons (#128)
* ENH: Increase unit-tests coverage of ``sdcflows.fieldmaps`` (#159)
* ENH: Optimize tensor-product B-Spline kernel evaluation (#157)
* ENH: Add a memory check to dynamically limit interpolation blocksize (#156)
* ENH: Massage TOPUP's fieldcoeff files to be compatible with ours (#154)
* ENH: Add a simplistic EPI masking algorithm (#152)
* ENH: Utility that returns the ``B0FieldSource`` of a given potential EPI target (#151)
* ENH: Write ``fmapid-`` entity in Derivatives (#150)
* ENH: Multiplex fieldmap estimation outputs into a single ``outputnode`` (#149)
* ENH: Putting the new API together on a base workflow (#143)
* ENH: Autogenerate ``B0FieldIdentifiers`` from ``IntendedFor`` (#142)
* ENH: Finalizing the API overhaul (#132)
* ENH: Keep a registry of already-used identifiers (and auto-generate new) (#130)
* ENH: New objects for better representation of fieldmap estimation (#114)
* ENH: Show FieldmapReportlet oriented aligned with cardinal axes (#120)
* ENH: New estimation API (featuring a TOPUP implementation!) (#115)
* DOC: Fix typo in docstring (#155)
* DOC: Enable NiPype's sphinx-extension to better render Interfaces (#131)
* MAINT: Drop Python 3.6 (#160)
* MAINT: Enable Git-archive protocol with setuptools-scm-archive (#153)
* MAINT: Migrate TravisCI -> GH Actions (completion) (#138)
* MAINT: Migrate TravisCI -> GH Actions (#137)
* MAINT: Minimal unit test and refactor of pepolar workflow node (#133)
* MAINT: Collect code coverage from tests on Circle (#122)
* MAINT: Test minimum dependencies with TravisCI (#96)
* MAINT: Add FLIRT config files to prepare for TOPUP integration (#116)