Implement /launch endpoint on job template

Partial implementation of:

https://trello.com/c/7uXHs7ze/14-require-admin-to-be-able-to-run-a-job-without-a-job-template

awx/api/views.py

@@ -1337,6 +1337,31 @@ class JobTemplateDetail(RetrieveUpdateDestroyAPIView):
     model = JobTemplate
     serializer_class = JobTemplateSerializer
 
+class JobTemplateLaunch(GenericAPIView):
+
+    model = JobTemplate
+
+    def get(self, request, *args, **kwargs):
+        obj = self.get_object()
+        data = {}
+        data['can_start_without_user_input'] = obj.can_start_without_user_input()
+        data['passwords_needed_to_start'] = obj.passwords_needed_to_start
+        data['ask_variables_on_launch'] = obj.ask_variables_on_launch
+        return Response(data)
+
+    def post(self, request, *args, **obj):
+        obj = self.get_object()
+        if not request.user.can_access(self.model, 'start', obj):
+            raise PermissionDenied()
+        new_job = obj.create_unified_job()
+        result = new_job.signal_start(**request.DATA)
+        if not result:
+            data = dict(passwords_needed_to_start=obj.passwords_needed_to_start)
+            return Response(data, status=status.HTTP_400_BAD_REQUEST)
+        else:
+            data = dict(job=new_job.id)
+            return Response(data, status=status.HTTP_202_ACCEPTED)
+
 class JobTemplateSchedulesList(SubListCreateAPIView):
 
     view_name = "Job Template Schedules"