injekt/slop — pull request #80 by kachick (2012-09-16 16:09:13+00:00)
Title: Specify the target ruby versions in gemspec.

I guess, Slop target ruby vesions are 1.8.7 or later.
Because below codes, and .travis.yml.

```ruby
&:to_s
```

I am glad that policy becomes clear.