Add a reference to the github repo in a footer

Closes gh-146

initializr/src/main/resources/static/css/spring.css

@@ -1,3 +1,10 @@
+html {
+    position: relative;
+    min-height: 100%;
+}
+body {
+    margin-bottom: 60px;
+}
 body, h1, h2, h3 {
     font-weight: 400;
     font-family: "Varela Round", sans-serif;
@@ -129,3 +136,17 @@ input[type=text] {
     color: #fff;
     background-color: #0097cf;
 }
+
+footer {
+    position: absolute;
+    bottom: 0;
+    width: 100%;
+    height: 60px;
+    background-color: #5d5d5d;
+    color: #eee;
+    padding: 20px 0;
+}
+
+footer a:hover, footer a:focus {
+    color: #6db33f;
+}

initializr/src/main/resources/templates/home.html

@@ -162,6 +162,12 @@
         </div>
     </div>
 </form>
+<footer>
+    <div class="container">
+        <p>start.spring.io is powered by <a href="https://github.com/spring-io/initializr/">Spring Initializr</a>
+            and <a href="https://run.pivotal.io">Pivotal Web Services</a></p>
+    </div>
+</footer>
 <script src="/js/jquery-1.11.3.min.js"></script>
 <script src="/js/typeahead.bundle.min.js"></script>
 <script src="/js/mousetrap.min.js"></script>