Removing trailing whitespace
[tests] removing test whether do_edit() exists

... because the method no longer works as simply as the test implied
[tests] removing read_db_file() test

It's no longer in the controller
[tests] removing skipped test for print_colors()

The print_colors() routine is just a test routine anyway, and doesn't really
need a test.
[tests] Removing the test for get_config() and a missing config file

The get_config() method isn't actually used anywhere, so it's questionable
if we want this test and its associated functionality.