Editorial: "that is check" -> "that checks"

PR: #310

Overview.html

@@ -7,7 +7,7 @@
 
 <p><a class="logo" href="https://whatwg.org/"><img alt="WHATWG" height="100" src="https://resources.whatwg.org/logo-fetch.svg" width="100"></a>
 <h1 id="cors">Fetch</h1>
-<h2 class="no-num no-toc" id="living-standard-—-last-updated-30-may-2016">Living Standard — Last Updated 30 May 2016</h2>
+<h2 class="no-num no-toc" id="living-standard-—-last-updated-1-june-2016">Living Standard — Last Updated 1 June 2016</h2>
 
 <dl>
  <dt>Participate:
@@ -1782,7 +1782,7 @@ <h4 id="http-requests"><span class="secno">4.2.2 </span>HTTP requests</h4>
 the <a href="#cors-protocol">CORS protocol</a> as the `<a href="#http-origin"><code title="http-origin">Origin</code></a>` header is sometimes
 included for other purposes too.
 
-<p>A <dfn id="cors-preflight-request">CORS-preflight request</dfn> is a <a href="#cors-request">CORS request</a> that is check to see if the
+<p>A <dfn id="cors-preflight-request">CORS-preflight request</dfn> is a <a href="#cors-request">CORS request</a> that checks to see if the
 <a href="#cors-protocol">CORS protocol</a> is understood. It uses `<code title="">OPTIONS</code>` as
 <a href="#concept-method" title="concept-method">method</a> and includes these
 <a href="#concept-header" title="concept-header">headers</a>:
@@ -5676,6 +5676,7 @@ <h2 class="no-num" id="acknowledgments">Acknowledgments</h2>
 Shivakumar Jagalur Matt,
 Simon Pieters,
 Srirama Chandra Sekhar Mogali,
+Steven Salat,
 Sunava Dutta,
 Surya Ismail,
 吉野剛史 (Takeshi Yoshino),

Overview.src.html

@@ -1710,7 +1710,7 @@ <h4>HTTP requests</h4>
 the <span>CORS protocol</span> as the `<code title=http-origin>Origin</code>` header is sometimes
 included for other purposes too.
 
-<p>A <dfn>CORS-preflight request</dfn> is a <span>CORS request</span> that is check to see if the
+<p>A <dfn>CORS-preflight request</dfn> is a <span>CORS request</span> that checks to see if the
 <span>CORS protocol</span> is understood. It uses `<code title>OPTIONS</code>` as
 <span title=concept-method>method</span> and includes these
 <span title=concept-header>headers</span>:
@@ -5512,6 +5512,7 @@ <h2 class=no-num>Acknowledgments</h2>
 Shivakumar Jagalur Matt,
 Simon Pieters,
 Srirama Chandra Sekhar Mogali,
+Steven Salat,
 Sunava Dutta,
 Surya Ismail,
 吉野剛史 (Takeshi Yoshino),