Add RFC keywords

Author: jubianchi

composer.json

@@ -2,7 +2,9 @@
     "name"       : "hoa/http",
     "description": "The Hoa\\Http library.",
     "type"       : "library",
-    "keywords"   : ["library", "http", "request", "response", "runtime"],
+    "keywords"   : ["library", "http", "request", "response", "runtime",
+                    "rfc2295", "rfc2518", "rfc3229", "rfc4918", "rfc5842", "rfc6585", "rfc7231", "rfc7232", "rfc7233",
+                    "rfc2324", "rfc7235", "rfc7237", "rfc2774"],
     "homepage"   : "http://hoa-project.net/",
     "license"    : "BSD-3-Clause",
     "authors"    : [