Don't set default dest in CLI

If no `dest` is passed, docopt would still force it to `sassdoc` and the
rest of the code would think `dest` was set explicitely via CLI, thus
overriding any `dest` from potential configuration file.

Author: valeriangalliat

src/cli.js

@@ -10,7 +10,7 @@ Options:
   -h, --help            Bring help.
   --version             Show version.
   -v, --verbose         Enable verbose mode.
-  -d, --dest=<dir>      Documentation folder [default: sassdoc].
+  -d, --dest=<dir>      Documentation folder.
   -c, --config=<path>   Path to JSON/YAML configuration file.
   -t, --theme=<name>    Theme to use.
   -p, --parse           Parse the input and output JSON data to stdout.