Support `config` command line option to specify a custom dojorc configuration file

[agubler]

Type: feature

The following has been addressed in the PR:

• [x] There is a related issue
• [x] All code has been formatted with prettier as per the readme code style guidelines
• [x] Unit or Functional tests are included in the PR

Description:

Adds support for specifying a custom configuration file that will be used instead of the default .dojorc file. This option will be available for all commands.

Resolves #286