Exclude buggy Toil 5.6

Exclude Toil version 5.6, because it contains a nasty file renaming bug, that is (sometimes) triggered in scatter jobs operating on Measurement Sets. See https://github.com/DataBiosphere/toil/issues/4101 for details.

Closes RAP-500

setup.py

@@ -38,9 +38,10 @@ setup(
                  'Intended Audience :: Science/Research',
                  'Operating System :: POSIX :: Linux',
                  'Topic :: Scientific/Engineering :: Astronomy'],
-    install_requires=['numpy', 'scipy', 'astropy', 'jinja2', 'shapely', 'toil[cwl]',
-                      'reproject', 'python-dateutil', 'Rtree', 'loess', 'lsmtool',
-                      'losoto', 'bdsf', 'python-casacore'],
+    install_requires=['numpy', 'scipy', 'astropy', 'jinja2', 'shapely',
+                      'toil[cwl]!=5.6', 'reproject', 'python-dateutil',
+                      'Rtree', 'loess', 'lsmtool', 'losoto', 'bdsf',
+                      'python-casacore'],
     scripts=['bin/rapthor',
              'bin/plotrapthor',
              'bin/concat_prefactor_files',