Pinned dparse to <0.5.0 on py27 due to an issue

Details:

* The dparse package is used by the safety command. pywbemtools
  invokes the safety command in the Makefile such that errors
  it returns are ignored. That's whx this issue did not surface
  immediately.

  dparse 0.5.0 released on 2020-03-14 introduced an infinite recursion
  problem that just surfaces on Python 2.7. See issue
  pyupio/dparse#46

  This change mitigates the issue by pinning dparse to <0.5.0 on
  Python 2.7.

Signed-off-by: Andreas Maier <andreas.r.maier@gmx.de>

dev-requirements.txt

@@ -23,6 +23,10 @@ python-coveralls>=2.8.0;
 
 # Safety CI by pyup.io
 safety>=1.8.4
+# dparse 0.5.0 has an infinite recursion issue on Python 2.7,
+#   see https://github.com/pyupio/dparse/issues/46
+dparse>=0.4.1,<0.5.0; python_version == '2.7'
+dparse>=0.4.1; python_version >= '3.4'
 
 # TODO: Remove the pinning of the pytest-cov version again once issue
 #       https://github.com/z4r/python-coveralls/issues/66

docs/changes.rst

@@ -50,6 +50,8 @@ Released: not yet
 * Corrected issue with use-pull general option that causes issues with using
   the 'either' option with servers that do not have pull. (See issue #530)
 
+* Pinned dparse to <0.5.0 on Python 2.7 due to an issue.
+
 **Enhancements:**
 
 * Test: Improved assertion messages in tests.