Workaround for apple compiler issue

- See boxen/our-boxen#528 for more info

app/views/splash/index.html.erb

@@ -15,7 +15,7 @@
         <div class="stamp"><%= view.user_org.html_safe %></div>
       <% end %>
       <h1>Welcome to Boxen</h1>
-      <textarea class="code" spellcheck="false" onclick="this.focus();this.select();">curl -s <%= view.script_url %> &gt; /tmp/install-boxen; bash /tmp/install-boxen</textarea>
+      <textarea class="code" spellcheck="false" onclick="this.focus();this.select();">curl -s <%= view.script_url %> &gt; /tmp/install-boxen; ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future bash /tmp/install-boxen</textarea>
       <h2>Run this command in your terminal to install Boxen on your machine.</h2>
       <h3>Go ahead. <a href="<%= view.script_path %>">Take a peek</a>.</h3>
     </div>