Add managed Lab 3 browser terminal deployment

ansible/roles/wiki/templates/courseware-runtime.json.j2

@@ -0,0 +1,5 @@
+{
+  "lab3TerminalUrl": "http://{{ courseware_url_host }}:{{ courseware_ports.wetty }}{{ courseware_wetty_base_path }}",
+  "lab3Username": "{{ courseware_student_username }}",
+  "lab3WorkingDirectory": "{{ courseware_lab3_dir }}"
+}