mspec tag [options] (FILE|DIRECTORY|GLOB)+

 Ask yourself:
  1. What specs to run?
  2. How to display the output?
  3. What tag action to perform?
  4. When to perform it?

 What specs to run
   -e, --example STR            Run examples with descriptions matching STR
   -E, --exclude STR            Exclude examples with descriptions matching STR
   -p, --pattern PATTERN        Run examples with descriptions matching PATTERN
   -P, --excl-pattern PATTERN   Exclude examples with descriptions matching PATTERN
   -g, --tag TAG                Run examples with descriptions matching ones tagged with TAG
   -G, --excl-tag TAG           Exclude examples with descriptions matching ones tagged with TAG
   -Z, --dry-run                Invoke formatters and other actions, but don't execute the specs

 How to display their output
   -f, --format FORMAT          Formatter for reporting: s:specdoc|d:dotted|h:html|u:unitdiff|a:*:spin
   -V, --verbose                Output the name of each file processed
   -m, --marker MARKER          Output MARKER for each file processed
       --int-spec               Control-C interupts the current spec only

 What action to perform and when to perform it
   -N, --add TAG                Add TAG with format 'tag' or 'tag(comment)' (see -Q, -F, -L)
   -R, --del TAG                Delete TAG (see -Q, -F, -L)
   -Q, --pass                   Apply action to specs that pass (default for --del)
   -F, --fail                   Apply action to specs that fail (default for --add)
   -L, --all                    Apply action to all specs

 Help!
   -v, --version                Show version
   -h, --help                   Show this message

 How might this work in the real world?

   1. To add the 'fails' tag to failing specs

     mspec tag path/to/the_file_spec.rb

   2. To remove the 'fails' tag from passing specs

     mspec tag --del fails path/to/the_file_spec.rb