BTS_airlines.py not wrapped in function

[bl-young]

Importing this module is causing errors due to a required local file

https://github.com/USEPA/flowsa/blob/ghgi-recursive-yaml/flowsa/data_source_scripts/BTS_Airlines.py

flowsa/flowsa/data_source_scripts/BTS_Airlines.py

Lines 6 to 7 in d7c9403

	with open(f'{settings.sourceconfigpath}BTS_Airlines.yaml') as f:
	config = flowsa_yaml.load(f)

This should be wrapped inside a function.

[bl-young]

@matthewlchambers This is causing errors in the github actions, and for us to run things, as we don't have access to the file here: https://github.com/USEPA/flowsa/blob/ghgi-recursive-yaml/flowsa/methods/flowbyactivitymethods/BTS_Airlines.yaml#L7

[matthewlchambers]

Hahaha, that absolutely should be wrapped in a function. My mistake.