Use pecan instead of wsme for trigger

The git trigger workflow was failing due to a bug in wsme.

This code turns off wsme and instead uses pecan for
TriggerController's post method.

Change-Id: Ibdf3d9b9a4fc7e4cdc8786fe13f9f6b4ae281055
Closes-Bug: #1315139
Merge "Use pecan instead of wsme for trigger"