Minor cleanup of `test_config.py`

[delirious-lettuce]

• Replace tabs with spaces

  Spaces are the preferred indentation method.

• Use parentheses to get rid of backslashes for line continuation

  The preferred way of wrapping long lines is by using Python’s implied line continuation inside parentheses, brackets and braces. Long lines can be broken over multiple lines by wrapping expressions in parentheses. These should be used in preference to using a backslash for line continuation.

[gjcarneiro]

Grr, it's because at my company we indent with tabs not spaces, which I really really hate, but...

[delirious-lettuce]

@gjcarneiro ,

Oh ok, I just thought it was a typo. No big deal, just trying to help out.