Login: display feedback.

app/styles/app.css

@@ -5,3 +5,47 @@
 .flakes-table thead tr {
   cursor: pointer;
 }
+
+/* BEGIN https://github.com/tobiasahlin/SpinKit */
+.spinner {
+  width: 40px;
+  height: 40px;
+
+  position: relative;
+  margin: 100px auto;
+}
+
+.double-bounce1, .double-bounce2 {
+  width: 100%;
+  height: 100%;
+  border-radius: 50%;
+  background-color: #333;
+  opacity: 0.6;
+  position: absolute;
+  top: 0;
+  left: 0;
+
+  -webkit-animation: bounce 2.0s infinite ease-in-out;
+  animation: bounce 2.0s infinite ease-in-out;
+}
+
+.double-bounce2 {
+  -webkit-animation-delay: -1.0s;
+  animation-delay: -1.0s;
+}
+
+@-webkit-keyframes bounce {
+  0%, 100% { -webkit-transform: scale(0.0) }
+  50% { -webkit-transform: scale(1.0) }
+}
+
+@keyframes bounce {
+  0%, 100% {
+    transform: scale(0.0);
+    -webkit-transform: scale(0.0);
+  } 50% {
+    transform: scale(1.0);
+    -webkit-transform: scale(1.0);
+  }
+}
+/* END https://github.com/tobiasahlin/SpinKit */