Update composer keywords

Author: zachborboa

composer.json

@@ -3,7 +3,10 @@
     "description": "PHP Curl Class is an object-oriented wrapper of the PHP cURL extension.",
     "homepage": "https://github.com/php-curl-class/php-curl-class",
     "license": "Unlicense",
-    "keywords": ["php", "curl", "class"],
+    "keywords": [
+        "php", "curl", "class", "api", "client", "framework", "http client",
+        "http", "json", "requests", "rest", "restful", "web service", "xml"
+    ],
     "authors": [
         {
             "name": "Zach Borboa"