Prepare for 2.3.3 (#361)

* Update CHANGELOG.md

* Make sure HHVM runs on Trusty

.travis.yml

@@ -11,7 +11,6 @@ php:
   - 5.6
   - 7.0
   - 7.1
-  - hhvm
 
 env:
   - TEST_COMMAND="composer test-all"
@@ -21,6 +20,8 @@ matrix:
     include:
         - php: 5.5
           env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" PREFER_COVERAGE=true
+        - php: hhvm
+          dist: trusty
 
 install:
     - travis_retry composer update ${COMPOSER_FLAGS} --prefer-source --no-interaction

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 The change log describes what is "Added", "Removed", "Changed" or "Fixed" between each release. 
 
+## 2.3.3
+
+### Changed
+
+- Using stable version of `php-http/multipart-stream-builder`
+- Improved tests
+
 ## 2.3.2
 
 ### Fixed