Add convenience method for gathering employee history context data

so we can reuse that for returning JSON from various views

tailbone/views/people.py

@@ -247,22 +247,22 @@ class PeopleView(MasterView):
             'instance_title': self.get_instance_title(person),
             'employee': employee,
             'employee_history': employee.get_current_history() if employee else None,
-            'employee_history_data': [],
+            'employee_history_data': self.get_context_employee_history(employee),
         }
 
-        # employee_history_data
+        use_buefy = self.get_use_buefy()
+        template = 'view_profile_buefy' if use_buefy else 'view_profile'
+        return self.render_to_response(template, context)
+
+    def get_context_employee_history(self, employee):
+        data = []
         if employee:
-            data = []
             for history in sorted(employee.history, key=lambda h: h.start_date, reverse=True):
                 data.append({
                     'start_date': six.text_type(history.start_date),
                     'end_date': six.text_type(history.end_date or ''),
                 })
-            context['employee_history_data'] = data
-
-        use_buefy = self.get_use_buefy()
-        template = 'view_profile_buefy' if use_buefy else 'view_profile'
-        return self.render_to_response(template, context)
+        return data
 
     def make_note_form(self, mode, person):
         schema = NoteSchema().bind(session=self.Session(),