Move all state variables into environment within package

[ethanplunkett]

Instead of using constants in the package or writing to variables to the global (user's) environment, store state variables in a config environment within the package.

• Create config environment and assign default values to it.

• Move most of the items in in globals.R to config by adding a prefix config$ when assigning and retrieving them. If there's any chance it would change in a different deployment it should be in config and not defined as a global constant in the package.

• Move state variables created by set_s3_config and retrieved by get_s3_config to the config environment. Replace assign() with config$option <- .

• Add Items in config to set:

  • local_temp_path
  • log_file_path,
  • log (flag to turn logging on and off)

• Update logging to honor log_file_path and log

• Update flow to honor local_temp_path

• Write function to set and retrieve options. See example

• Move set_s3_config and get_s3_config into s3_config.R (from flow.R)

• Set all list items as variables in config using config$...