standardize database parameter configuration

[shaycrk]

Database connection parameters seem to be specified with different keys and connections established in different ways across triage components. We should standardize these to use a single method for connecting to the database.

A couple of examples (but may not be exhaustive):

• Triage CLI
• Postmodeling utils
• Audition Tutorial

[nanounanue]

We should use the environment variable always, or the connection url

[jesteria]

Yeah, my understanding was that we had standardized it, in so far as the Triage library only requires some SQLAlchemy engine, and the Triage CLI accepts either a database URI specified via process environment variable or ... some, specific, YAML.

I think this raises inconsistencies which might only remain in tutorials.

E.g. I tried to get postmodeling/contrast/utils/aux_funcs.py:create_pgconn removed – postmodeling doesn't really use it – but I was told it's used in the iPython notebook tutorial.

So perhaps it's just these tutorials that are at issue?

[ecsalomon]

See also the readme and example database profile for the results schema. Despite my improvements, it still contains internal inconsistencies as well as inconsistencies with the triage standard methods.