use config file with CURL loader

[svrnm]

Description

fixes #52

Type of Change

• Bugfix
• New Feature
• Breaking Change
• Refactor
• Documentation
• Other (please describe)

[noMoreCLI]

@svrnm, as this is a breaking change. Can we have the option to pass the configuration either through an env variable OR through a config file? There might be deployment envs in the future, where passing a file is more challenging than an env variable (ECS or other container PaaS services come in mind)

[svrnm]

@svrnm, as this is a breaking change. Can we have the option to pass the configuration either through an env variable OR through a config file? There might be deployment envs in the future, where passing a file is more challenging than an env variable (ECS or other container PaaS services come in mind)

See 7d930dd, I changed it such that it checks if the file exists and if so reads from it otherwise it will use environment variables (if available)