Updated MailChimp Adapter

- Reordered Imports
- Started using VendorName for all Failure Messages
Updated Mandrill Adapter

- Reordered Imports
- Started using VendorName for all failure messages
- Renamed payloadBodyToEventList -> payloadBodyToEvents
- Added ability to remove the field “event” -> “type” from the event
JSON in reformatParameters
Updated Mandrill Spec to reflect changes to Adapter
Updated PagerDuty spec to reflect changes to Adapter
Updated PagerDuty Adapter

- Reordered imports
- Started using VendorName for all failure messages
Updated Pingdom Adapter

- Reordered imports
- Started using VendorName for all failure messages