Add development only flag to lti1.3 ff
Add development only flag to lti1.3 ff

closes PLAT-3852

Test Plan:
n/a

Change-Id: Ia57a96542814edbf25a823cfe3d729dd7abff586
Reviewed-on: https://gerrit.instructure.com/167593
Tested-by: Jenkins
Reviewed-by: Xander Moffatt <27f70fe194da423604e6e0a63a3de19814736fa9@instructure.com>
QA-Review: Xander Moffatt <27f70fe194da423604e6e0a63a3de19814736fa9@instructure.com>
Product-Review: Xander Moffatt <27f70fe194da423604e6e0a63a3de19814736fa9@instructure.com>

djbender/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms