Returns a function which accepts an event and sends it to cloudwatch. Usage:

(cloudwatch {:access-key "AKJALPVWYQ6BFMVLSZDA"
             :secret-key "ZFEemkafy0paNMx5JcinMUiOC4dcMKhxXCL85DhM"})

(cloudwatch {}) will make use of IAM Instance Profile.

Options:

• :access-key AWS access key of your AWS Account.
• :secret-key AWS secret key for the above access key.
• :endpoint AWS Endpoint for posting metrics(changes with AWS region).
• :namespace AWS CloudWatch namespace.

Accepts riemann event and converts it into cloudwatch datapoint.