Add uncommitted spec example for B::Transport.reachable?
user
```ruby
require "spec_helper"

describe Bunny::Transport, ".reachable?" do
  it "returns true for google.com, 80" do
    Bunny::Transport.reacheable?("google.com", 80, 1).should be_true
  end

  it "returns true for google.com, 8088" do
    Bunny::Transport.reacheable?("google.com", 8088, 1).should be_false
  end

  it "returns false for google1237982792837.com, 8277" do
    Bunny::Transport.reacheable?("google1237982792837.com", 8277, 1).should be_false
  end
end
```
assistant