Remove EmulateAsyncClient and client-tools dependency

Author: sagikazarmark

composer.json

@@ -13,8 +13,7 @@
     "require": {
         "php": ">=5.4",
         "php-http/httplug": "1.0.0-alpha2",
-        "php-http/message-factory": "^1.0",
-        "php-http/client-tools": "^0.1@dev"
+        "php-http/message-factory": "^1.0"
     },
     "require-dev": {
         "phpspec/phpspec": "^2.4",