Update Guzzle to ~4.0 and set travis

Now the Client has just a send method and handle an IntercomObjectInterface which has all informations about the API call

pick d7ab823 Rename the command for accreditations
pick d7ab823 Rename the command for accreditations
pick d7ab823 Rename the command for accreditations
pick d7ab823 Rename the command for accreditations