Add a `#have_put` matcher to test `#put` action.

With this matcher you can test if a content (i.e, a string) is
uploaded to the server. You can also test the path.

Example:

  it "should have put" do
    @configuration.put 'some: content', '/config.yml'
    @configuration.should have_put('some: content').to('/config.yml')
  end
Use #select instead of #reduce in uploads detection.

The combination of #select + #values is clearer than the #reduce method.
Merge pull request #13 from jhbabon/add-have-put-matcher

Add a `#have_put` matcher to test `#put` action.