Update ddt dependency after upstream bug fix.

dev_requirements.txt

@@ -20,8 +20,6 @@ six
 # those are the additional packages required to run the tests
 pyfakefs
 certifi
-# FIXME: remove strict version when https://github.com/datadriventests/ddt/issues/83 is fixed.
-#        (also remove in setup.py)
-ddt==1.3.1
+ddt>=1.4.1
 mock
 pytest

setup.py

@@ -60,7 +60,7 @@ setup(
     ],
 
     test_suite='tests',
-    tests_require=['pyfakefs>=3.4', 'mock', 'ddt==1.3.1', 'certifi', 'pytest'],
+    tests_require=['pyfakefs>=3.4', 'mock', 'ddt>=1.4.1', 'certifi', 'pytest'],
 
     # in order to avoid 'zipimport.ZipImportError: bad local file header'
     zip_safe=False,