Update workflow on documenting changes

Only in whatsnew and no longer also in release.rst
TST: fix intermittent dict_complex test failures

`test_dict_complex` and `test_dict_numpy_complex` would give occasional
test failures on Python 3.4.  The test was written to depend on the
order of values from `dict.values()`; remove that dependency.

Closes gh-7293.
Merge pull request #7298 from matthew-brett/fix-dict-complex-failures

TST: fix intermittent dict_complex test failures
BUG: Index.delete doesnt preserve name and other attrs
CLN/TST Remove compat.scipy
Merge pull request #7296 from clham/CompatScipy

CLN/TST remove compat.scipy
Update CONTRIBUTING.md

mention pep8radius
TST: missing import of nose in test_tseries.py
Merge pull request #7302 from sinhrks/delete

BUG: Index.delete doesnt preserve name and other attrs
BUG: CustomBusinessDay apply raises NameError when np.datetime64 is passed