Skew

Fixed a bug when enumerating resources in a Cloudformation Stack.

Added support for API Gateway, SNS, and Elastic Beanstalk.

Moved tests to use placebo. Changed functions that take optional args (e.g. `aws_creds`) to use keyword args to clean up the code a bit.

Fixed 79 and changed dependency from botocore to boto3.

Changed the botocore dependency to the latest released version.

Added support for Lambda functions and CloudFormation stacks. Also change the way `aws_creds` can be passed in for automated use. Rather than use a globalvar the creds are now passed into the `scan` function. Also removed the AWS client cache. It offered little benefit and caused significant problems in long-running applications.