Version Bump v3.9.3: sendgrid#93 Don't overwrite headers

Author: thinkingserious

CHANGELOG.md

@@ -3,6 +3,10 @@ All notable changes to this project will be documented in this file.
 
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## [3.9.3] - 2018-03-11
+### Fixed
+- Fixes [#584](https://github.com/sendgrid/sendgrid-php/issues/584), PR [#93](https://github.com/sendgrid/php-http-client/pull/93): Don't overwrite headers set from upstream dependencies.
+
 ## [3.9.2] - 2018-03-10
 ### Fixed
 - Fixes [#12](https://github.com/sendgrid/php-http-client/issues/12), PR [#91](https://github.com/sendgrid/php-http-client/pull/91): Curl Options broken as array merge does not preserve keys. 

README.md

@@ -39,7 +39,7 @@ Add php-http-client to your `composer.json` file. If you are not using [Composer
 ```json
 {
   "require": {
-    "sendgrid/php-http-client": "~3.9.2"
+    "sendgrid/php-http-client": "~3.9.3"
   }
 }
 ```

composer.json

@@ -2,7 +2,7 @@
     "name": "sendgrid/php-http-client",
     "description": "HTTP REST client, simplified for PHP",
     "type": "library",
-    "version": "3.9.2",
+    "version": "3.9.3",
     "homepage": "http://github.com/sendgrid/php-http-client",
     "keywords": ["SendGrid", "HTTP", "REST", "API", "Fluent"],
     "license": "MIT",