Center footer

src/main/webapp/scripts/app/fragments/footer.html

-<div style="text-align: right; padding-top: 3em;">
-    <img src="resources/images/spring-pivotal-logo.png" alt="Sponsored by Pivotal"/>
-</div>
-
+<div class="container">
+    <div class="row">
+        <div class="col-12 text-center"><img src="/resources/images/spring-pivotal-logo.png"
+                                             alt="Sponsored by Pivotal"/></div>
+    </div>
+</div>
\ No newline at end of file