fix httpbin.org hostname in psr7.rst

docs/psr7.rst

@@ -224,7 +224,7 @@ When creating a request, you can provide the URI as a string or an instance of
 
 .. code-block:: php
 
-    $response = $client->get('http://httbin.org/get?q=foo');
+    $response = $client->get('http://httpbin.org/get?q=foo');
 
 
 Scheme
@@ -236,9 +236,9 @@ scheme can be set to "http" or "https".
 
 .. code-block:: php
 
-    $request = $client->createRequest('GET', 'http://httbin.org');
+    $request = $client->createRequest('GET', 'http://httpbin.org');
     echo $request->getUri()->getScheme(); // http
-    echo $request->getUri(); // http://httpbin.com/get
+    echo $request->getUri(); // http://httpbin.org/get
 
 
 Host
@@ -249,7 +249,7 @@ Host header.
 
 .. code-block:: php
 
-    $request = new Request('GET', 'http://httbin.org');
+    $request = new Request('GET', 'http://httpbin.org');
     echo $request->getUri()->getHost(); // httpbin.org
     echo $request->getHeader('Host'); // httpbin.org
 
@@ -261,9 +261,9 @@ No port is necessary when using the "http" or "https" schemes.
 
 .. code-block:: php
 
-    $request = $client->createRequest('GET', 'http://httbin.org:8080');
+    $request = $client->createRequest('GET', 'http://httpbin.org:8080');
     echo $request->getUri()->getPort(); // 8080
-    echo $request->getUri(); // https://httpbin.com:8080
+    echo $request->getUri(); // https://httpbin.org:8080
 
 
 Path
@@ -273,7 +273,7 @@ The path of a request is accessible via the URI object.
 
 .. code-block:: php
 
-    $request = new Request('GET', 'http://httbin.org/get');
+    $request = new Request('GET', 'http://httpbin.org/get');
     echo $request->getUri()->getPath(); // /get
 
 The contents of the path will be automatically filtered to ensure that only
@@ -290,7 +290,7 @@ URI object owned by the request.
 
 .. code-block:: php
 
-    $request = new Request('GET', 'http://httbin.org/?foo=bar');
+    $request = new Request('GET', 'http://httpbin.org/?foo=bar');
     echo $request->getUri()->getQuery(); // foo=bar
 
 The contents of the query string will be automatically filtered to ensure that