Abstract a function for returning all files in a dir or the file
Change which redact file has the suffix

Also change redact test to expect different files.

This fixes #59. The usage is beautiful too.
Extract a function for performing a redaction on three files
Add an environment variable "COMPLETE_SUFFIX"
Add some functions for deriving redaction filenames from a base
Pull name derivation into redact function
Remove some noise from the test output
Don't ignore specific files when redacting