Merge branch 'master' into refactoring

# Conflicts:
#	composer.json

Author: misantron

.travis.yml

@@ -1,19 +1,12 @@
 language: php
 before_script:
-- phpenv local 5.4
 - composer install --dev --no-interaction
-- phpenv local --unset
 - cd test/unit
 script:
 - ../../vendor/bin/phpunit . --bootstrap bootstrap.php --filter test* --coverage-clover clover.xml
-after_script:
-- cd ..
-- phpenv local 5.4
-- phpenv local --unset
 php:
-- 5.4
-- 5.5
 - 5.6
+- 7.0
 env:
   global:
   - secure: eUN0huKA436uIkISu6V3yW01/gZHC6slBvlnprMPEhzclU2szH6qhWEXWS5CcOG6EEDBReqLZdNAwu+FC69KGFO9+6oW2GQQLSsfEViqFi/Ig2N0r4EBO4jLRebgq0GOfetPwQvJH27d8BCiloPy8rXBb5pskxSNw4B4bRyXHz4=

CONTRIBUTING.md

@@ -64,7 +64,7 @@ We welcome direct contributions to the php-http-client code base. Thank you!
 
 ##### Prerequisites #####
 
-- PHP 5.2 through 5.6
+- PHP 5.6 or 7.0
 - [Composer](https://getcomposer.org/)
 
 ##### Initial setup: #####

README.md

@@ -10,6 +10,12 @@ All updates to this library is documented in our [CHANGELOG](https://github.com/
 
 # Installation
 
+## Prerequisites
+
+- PHP version 5.6 or 7.0
+
+## Install with Composer
+
 Add php-http-client to your `composer.json` file. If you are not using [Composer](http://getcomposer.org), you should be. It's an excellent way to manage dependencies in your PHP application.
 
 ```json

composer.json

@@ -21,7 +21,7 @@
         }
     ],
     "require": {
-        "php": ">=5.4"
+        "php": ">=5.6"
     },
     "autoload": {
         "psr-4": {