merge develop, add mobile nav component

src/components/mobile_nav/mobile_nav.js

@@ -0,0 +1,35 @@
+import SideDrawer from '../side_drawer/side_drawer.vue'
+import Notifications from '../notifications/notifications.vue'
+import { unseenNotificationsFromStore } from '../../services/notification_utils/notification_utils'
+
+const MobileNav = {
+  components: {
+    SideDrawer,
+    Notifications
+  },
+  data: () => ({
+    notificationsOpen: false
+  }),
+  computed: {
+    unseenNotifications () {
+      return unseenNotificationsFromStore(this.$store)
+    },
+    unseenNotificationsCount () {
+      return this.unseenNotifications.length
+    },
+    sitename () { return this.$store.state.instance.name }
+  },
+  methods: {
+    toggleMobileSidebar () {
+      this.$refs.sideDrawer.toggleDrawer()
+    },
+    toggleMobileNotifications () {
+      this.notificationsOpen = !this.notificationsOpen
+    },
+    scrollToTop () {
+      window.scrollTo(0, 0)
+    }
+  }
+}
+
+export default MobileNav