Switched Keen IO PHP SDK to use Guzzle Web Service Client

Added support for:
Bulk Loading
Parallel Requests
Data Analysis methods
Service Description and Version of Webservice Client

Updated Readme and Unit Tests
Updated client to allow operations to be called with the event collection as the first argument - to better conform with other Keen IO libraries.  Updated docs to reflect change.
merged back from pull request branch, fixed some formatting/comments
Changed spaces to psr-2
PSR2 & switching travis badge back to keenlabs repo