Cloning the input data before swapping receiver/sender

[fribeiro-keeps]

In index.js, when the sender/receiver names are switched, both sender and receiver are set to the initial receiver.
With this changes, we create a clone of that data before swapping and the swap will now be successful.

[coveralls]

Coverage remained the same at 100.0% when pulling 93897fc on keeps:fribeiro into 53b0db6 on amida-tech:master.