Slight change in caption for lattice select.

common/lib/capa/capa/templates/crystallography.html

@@ -2,7 +2,7 @@
     <div class="crystalography_problem" style="width:${width};height:${height}"></div>
 
     <div class="input_lattice">
-        Type: <select></select>
+        Lattice: <select></select>
     </div>
 
     <div class="script_placeholder" data-src="/static/js/raphael.js"></div>