AWS SDK 2.0.0+ support

AWS is working on the latest version of their Ruby SDK and currently this library doesn't seem to support it.

```
Resolving dependencies........
Bundler could not find compatible versions for gem "aws-sdk":
  In Gemfile:
    fake_sns (>= 0) ruby depends on
      aws-sdk (~> 1.30) ruby

    aws-sdk (2.0.5.pre)
```
