Added missing file methods

• Added download to the Files resource.
• Added ListsAttachedFiles trait to Deals.

Fixes bug when using Entity methods

Merge pull request #19 from mauriciovander/patch-1

BugFix

1.0.0: Merge pull request #14 from msieb/master

fixed wrong usage of request attribute in traits

0.3.3

Added emailMessages to deals

0.3.2

Fixes sending array of parameters

0.3.1

Minor documental updates

Removed helpers dependence

0.2.4

Update README.md