the_platinum_searcher 1.6.4 (new formula)

``the_platinum_searcher`` (``pt``) is code search tool, similar to ``ack`` and ``the_silver_searcher`` (``ag``), but is written in Go to enable easier multi-platform support.
``pt`` doesn't seem to return an exit code for positive/negative search results. Instead, assuming the command ran properly, ``pt`` only returns something if a match was found (example below). In this case, would it be enough to test that ``pt`` returns a non-empty string on a positive search result and an empty string on a negative search result?

```bash
# pt finds a match of 'Hello World!' on line 1 of hello.txt
> pt 'Hello World!' hello.txt
hello.txt:
1:Hello World!

# pt doesn't find a match
> pt 'Foo Bar' hello.txt
> 
```