replace datadog with dogapi gem, which is the one used by the plugins

Author: eheydrick

CHANGELOG.md

@@ -4,6 +4,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This CHANGELOG follows the format listed at [Keep A Changelog](http://keepachangelog.com/)
 
 ## [Unreleased]
+### Changed
+- Replace `datadog` with `dogapi` gem as that's the current dependency for this plugin (@eheydrick)
 
 ## [1.0.0] - 2017-05-17
 ### Added

sensu-plugins-datadog.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |s|
   s.test_files             = s.files.grep(%r{^(test|spec|features)/})
   s.version                = SensuPluginsDatadog::Version::VER_STRING
 
-  s.add_runtime_dependency 'datadog', '0.1.0.alpha'
+  s.add_runtime_dependency 'dogapi',       '~> 1.27'
   s.add_runtime_dependency 'sensu-plugin', '~> 1.2'
 
   s.add_development_dependency 'bundler', '~> 1.7'