Allow for specifying a config path when using ConnectionResolver

[matt2930]

Describe the feature as you'd like to see it
I want to be able to specify a custom config path without setting an extra environment variable.

What do we currently have to do now?
The current implementation of ConnectionResolver and ConnectionFactory does the following:

1. ConnectionResolver inits ConnectionFactory
2. When creating a new transaction, ConnectionFactory will run make, which calls DB = load_config().DB
3. load_config() will either use the default config path, or use the DB_CONFIG_PATH env var

Additional context
The load_config function already has a config_path argument. So, my proposal is to:

• Add an optional config_path argument to ConnectionResolver

• Add an optional config_path argument to ConnectionFactory

• Pass through that config_path from ConnectionResolver to the initialization of ConnectionFactory

• Use the config_path in load_config

• Is this a breaking change?