KAT-55: Adding the import for the following page...

KAT-55: Adding the import for the following page breathing_frequency_per_minute.dart and the activation of the button JA for the navigation to the next page.

rescueapp/lib/start_triage_system/spontaneous_breathing_present.dart

 import 'package:flutter/material.dart';
 import 'after_opening_airways.dart';
+import 'breathing_frequency_per_minute.dart';
 
 class SpontaneousBreathingPresent extends StatefulWidget {
   SpontaneousBreathingPresent({Key key, this.title}) : super(key: key);
@@ -94,7 +95,13 @@ class _SpontaneousBreathingPresentState
                                 fontWeight: FontWeight.w600,
                                 color: Colors.blue[900])),
                         color: Colors.blue,
-                        onPressed: null ))),
+                        onPressed: () {
+                          Navigator.push(
+                            context,
+                            MaterialPageRoute(
+                                builder: (context) => BreathingFrequencyPerMinute()),
+                          );
+                        } ))),
             SizedBox(
               height: 10,
             ),