Fixed a typo in spotcrime case study

case-study/spotcrime.html

@@ -11,7 +11,7 @@ <h1>SpotCrime</h1>
 <section>
   <h2>The Problem</h2>
   <figure class="right">
-    <img src="{{ site.baseurl }}/images/spotcrime-case-study/spotcrime-2.jpg" alt="SpotCrime on and iPad">
+    <img src="{{ site.baseurl }}/images/spotcrime-case-study/spotcrime-2.jpg" alt="SpotCrime on an iPad">
     <figcaption>SpotCrime is the most comprehensive online source of crime information and provides crime maps and crime alert emails.</figcaption>
   </figure>
   <p><a href="http://spotcrime.com">SpotCrime</a> aggregates crime data from police departments all over the United States, maps the data, and provides email crime alerts. SpotCrime’s data tracking helps both police departments and citizens build safer communities.</p>