Document swift example.

[lindenle]

It would be nice to have a swift example (I am trying to figure it out at the moment).

For example I think in our installation we don't have https access and also we need to use ec2 keys and signatures...how do we do this?

[lindenle]

@branan - I have this working using the swift s3 API plus the commits I just opened in #7. the example would be something like:

s3file { "/Users/me/test.jar": 
    s3_url => "http://openstack.server6481" 
    source => "/bucket/test.jar", 
    s3_access_key => "xxxxxxxxxx", 
    s3_secret_key  => "xxxxxxxxxxx", 
    logoutput => false
 }