TST: more cleaning of yahoo/google testing
fixes yet another bug with yahoo/google testing

that basically invalidates the test
these should be definite values assuming no network issue (which should raise)
or a parsing error (raise also) or just no data for some reason (I'll bet this is it)
 the point is that you can't know if the network fails. it seems pointless to parse the warnings. the best solution would be to put a nan there.
 alright i broke down and am now checking the warnings for the symbols
 closing. going to reopen cleaning of data.py
 https://travis-ci.org/jreback/pandas/jobs/8570082

?
 the issue of no html. just now, lxml will read and try to parse but then no elements so it throws this error. before was the equally cryptic `AttributeError` when trying to call methods on `None`
 should probably revert back the call to `getroot()` and check for `None`ity
 ok....so this is an error then (when/how you catch it up 2 you)....

the return of this function in this case (since you got NO data) should be to raise some kind of error, maybe DataError?

(as opposed to getting some data, in which case you could return nan for the ones you don't get)
 oh gosh i just found a list in a default parameter...>:O
