Update README

Author: Xerkus

README.md

@@ -5,8 +5,8 @@
 
 zend-router provides flexible HTTP routing.
 
-Routing currently works against the [zend-http](https://github.com/zendframework/zend-http)
-request and responses, and provides capabilities around:
+Routing currently works against [PSR-7 HTTP message interfaces](http://www.php-fig.org/psr/psr-7/)
+server requests, and provides capabilities around:
 
 - Literal path matches
 - Path segment matches (at path boundaries, and optionally validated using regex)
@@ -16,7 +16,7 @@ request and responses, and provides capabilities around:
 - Hostname
 
 Additionally, it supports combinations of different route types in tree
-structures, allowing for fast, b-tree lookups.
+structures, allowing for fast lookup.
 
 ## Installation