Mobile view (dexlab-io#78)

* The Tip component is called with the appropiate parameters from
  inside the mobile view, so that it renders correctly.
* The Watcher object is initiated as soon as the Tip component is
  loaded in case it has the active tab. This didn't happen before as
  the tab navigation allowed it to start after the component was loaded.

src/pages/Dashboard/components/Tip.js

@@ -56,6 +56,9 @@ class Tip extends Component {
     store.fetch.pos().subscribe(async result => {
       const posAddress = result.data.pos.address;
       this.setState({ posAddress });
+      if(this.props.active) {
+        this.startWatcher();
+      }
     });
   }
 

src/pages/Dashboard/mobile.view.js

@@ -36,7 +36,10 @@ export default function() {
               </React.Fragment>
             )}
             {activeTab === 'recentPayments' && <RecentPayments />}
-            {activeTab === 'tip' && <Tip onClose={this.onCloseTip} />}
+            <Tip
+              active={activeTab === 'tip'}
+              onTipReceived={this.onTipReceived}
+            />
           </div>
         ) : (
           <div>Pos address is empty</div>