Updated how table extends data

[kjdoore]

The table method limited the extended prediction range to only include discharge values <= max(discharge) * 1.1. This seems confusing for a user, since one would typically want to extend stage and not discharge (i.e., extend the observed data range and see the resulting predictions). I have simply updated table method to not truncate the tabled data by discharge.

[thodson-usgs]

thanks @kjdoore! I'm not saying it's right, but that was intentional. My understanding was that operationally, they're allowed to extrapolate discharge 10% above the largest observation. I'll leave this issue open for now and take this up with some operational folks to get a sense of their preference.

[kjdoore]

Sounds good. It was a suggested change mainly based on my intuition of how the method should work. No need to implement it if limiting the discharge is preferred.