Merge pull request #15 from jeanphix/master

Make it more DRY
Add ability to push large stack templates to S3
InstanceType is not required (defaults to m1.small)
Add AssociatePublicIpAddress property for AutoScaling LaunchConfiguration
Make Tags an AWSHelperFn to make it easier to assign
Clean up "required" error checking and handle property types better
Resource property types should not be in a Properties dictionary

A previous change caused resource property types to be put into a
Properties dictionary. This fixes that regression.
Bumping version to 0.3.1
Convert VPCDHCPOptionsAssociation to not have __init__

This is inline with the big change in the last pull request. Nice commit
message huh?
Fix Output, Parameter and UpdatePolicy to not output a Properties dict
Fix pep8
Raise a ValueError if adding a duplicate object to the template
Review feedback: rename _duplicatekey() to handle_duplicate_key()
Set the correct dictname for UpdatePolicy
Bumping version to 0.3.2
Fix Ref() to output the name only [GH-17]

Ref needed to be changed to look for BaseAWSObject.
Add Ref test.
Fix some IAM issues

- Make Policy property work again
- Policy prop should be Users, not User
- Have more explicit error checking with list types
Bumping version to 0.3.3
Adding separators options to print to json function