Remove maxlength from search field (#56)

There are packages with names that are longer than 30 characters and the
user experience is confusing with the current limit.

Author: michaeljones

lib/diff_web/templates/search/search.html.leex

@@ -9,7 +9,6 @@
       name="q"
       value="<%= @query %>"
       placeholder="Search..."
-      maxlength="30"
     />
     <div class="suggestions">
       <%= if length(@suggestions) > 0 do %>