Config file for .notifyreg location

[Taylor Dawson]

Most CLI's that store data files have the option to specify where they would like the file to be stored. Right now it is hard coded. I was thinking of .notifyconfig file:

{
  "regFilePath" : "~/.notifyreg"
}

It would also help with testing (#38 ). I was using mock-js to create a mock filesystem for the tests but that creates intermitten issues. With a config file I could change the file before executing tests.

[Taylor Dawson]

Closed in lieu of #41.