add login test message

frontend/resources/styles/common/framework.scss

@@ -1077,3 +1077,13 @@ input[type=range]:focus::-ms-fill-upper {
     fill: $color-white;
   }
 }
+
+.message-inline {
+  background-color: $color-info;
+  color: $color-info-darker;
+  margin-bottom: 1.2rem;
+  padding: .8rem;
+  p {
+    margin: 0;
+  }
+}

frontend/src/uxbox/main/ui/auth/login.cljs

@@ -40,6 +40,8 @@
                                    :password (:password data)})))]
       [:form {:on-submit on-submit}
        [:div.login-content
+        [:div.message-inline.hide
+         [:p "UXBOX is currently on alpha version. That means that you're going to use a non-stable environment. Sorry for the inconvenience."]]
         [:input.input-text
          {:name "email"
           :ref "email"