Fixed broken tests for the language API (GoogleCloudPlatform#203)

Author: Takashi Matsuo

language/api/composer.json

@@ -1,8 +1,11 @@
 {
     "require": {
-        "google/cloud": "0.9",
+        "google/cloud": "~1.0|~0.11",
         "symfony/console": "^3.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "~4.0"
+    },
     "autoload": {
         "psr-4": {
             "Google\\Cloud\\Samples\\Language\\": "src/"