Include somesweeper to LOAD_PATH

I got this.

```
$ ./bin/somesweeper 
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- somesweeper/command (LoadError)
	from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
```

It seems your gem isn't published. You should include path or update README adding `bundle exec rake install`.