Landsat 5 coverage?

Nobody has claimed this yet.

First, thank you very much for the great tool set!
I'm using it for processing Landsat 5 L1 products, which works quite well as I can tell:

$ rio toa reflectance --dst-dtype 'uint8' -p -t '.*/LT05.*\_B{b}.TIF' ...

Also TOA brightness temp. works, with a minimal change to "rio-toa/rio_toa/brightness_temp.py":
K1 = toa_utils._load_mtl_key(mtl,
['L1_METADATA_FILE',
'THERMAL_CONSTANTS',
'K1_CONSTANT_BAND_'],
band)
K2 = toa_utils._load_mtl_key(mtl,
['L1_METADATA_FILE',
'THERMAL_CONSTANTS',
'K2_CONSTANT_BAND_'],
band)

Then I can use it right away:
$ rio toa brighttemp -d 'uint8' -t '.*/LT05.*\_B{b}.TIF' ...

I'd suggest two things:
1. Make the thermal constants string a wild card, e.g. "*THERMAL_CONSTANTS". To accept both LS8 and LS5 (and maybe other Landsat products?).
2. Mention in the README that LS5 would also work. I was almost turned down by just reading LS8 there.

Thank you!

Start in rio-toa/rio_toa/brightness_temp.py and inspect the _load_mtl_key calls shown in the issue, then check the README's Landsat support wording. Done means Landsat 5 thermal constants are accepted by brighttemp and the README no longer implies support is limited to Landsat 8; exercise the documented rio commands with Landsat 5 inputs.

Written by the indexing model from the issue text.