API: raise on header=bool in parsers
closes #6113

Passing `header=True|False` to `read_csv` (and brethren), `read_excel`, and `read_html` will now  raise a `TypeError`, rather than being coerced to an int.

I had thought about converting `False` to `None` but thought that could break someone's code in a very subtle way if they were somehow depending on the old behavior.  But happy to change that if it seems better.

If you want to push this in for 0.17 I can add a doc-note or this could easily wait.

@chris-b1 if you add a release note (put in the API section) can add for 0.17.0
 @jreback added a doc note and testing for the True case.
 tiny doc-change. ping when you push
 @jreback thanks, made that change
 thank you sir!
 Nice!
