FIX: Fix encoding to allow StataReader to read urls

[bashtage]

Fix encoding so that StataReader can correctly read URLs

closes #9231

[bashtage]

This fix is not finished - mostly using it to document the issue. The StringIO is returning unicode while unpack expects bytes (or string on Python 2). This simply encodes the unicode to a new StringIO object, and is very ugly.

[bashtage]

@jreback @jseabold Should be fixed now. I left in the url read for now simply to to verify once that it works. I will delete this basic test once it goes green.

[bashtage]

One timed out, the others all passed, so it seems ready, barring other issues in the method I used.

[jreback]

make these double back ticks on both sides of the word

[jreback]

minor comment, I restarted the stalled job

[bashtage]

@jreback Looks good. Let me know if you need me to rebase.

[jreback]

@bashtage thanks!