eval's KEYS and ARGV are now lua tables

[NimrodParasol]

During eval operation, KEYS and ARGV are now passed as Lua tables instead of Python lists.
This allows for iteration over them within the Lua script

This is a fix to the error described in issue 204

[coveralls]

Coverage remained the same at 98.483% when pulling 26b2738 on NimrodParasol:eval-keys-args-lua-objects into c3c45af on jamesls:master.

[bmerry]

Thanks, I'd missed that this was a separate PR to the other one.