TST: test_read_clipboard_infer_excel warning

[jreback]

pandas/tests/io/test_clipboard.py::TestClipboard::()::test_read_clipboard_infer_excel
  /home/travis/build/jreback/pandas/pandas/io/clipboards.py:63: ParserWarning: Falling back to the 'python' engine because the 'c' engine does not support regex separators (separators > 1 char and different from '\s+' are interpreted as regex); you can avoid this warning by specifying engine='python'.
    return read_table(StringIO(text), sep=sep, **kwargs)

[jreback]

cc @gfyoung if you'd take a look

[gfyoung]

There are two ways to fix this:

1. Pass in engine='python'
2. Assert that a warning gets issued (out of our control if their data requires multi-char separator and their defaulting to engine='c' in `read_table)

Thoughts?

[jreback]

yeah I think the engine='python' default may be ok here to avoid the warning, though maybe only need to do this if we are passing in a non-whitespace delimiter.

[gfyoung]

yeah I think the engine='python' default

I don't think the default should be changed. Rather, we should just pass in engine='python' for the test.

[jreback]

sgtm