Adds support for passing the pem key when scp'ing the data file to the bee instance

The scp was failing because it doesn't specify the .pem key in the command.  This includes it in the command.
Fixes support for posting contents of a file

In order for the contents of a file to be posted with ab you must proceed the file path with an @ symbol.
Removing the @ symbol.  Was getting confused with curl.  Oops.
Merge pull request #63 from Altonymous/patch-2

Adds support for passing the pem key when scp'ing the data file to the bee instance