Insert Pivotal Tracker story id into Git commit messages

# Story id of feature from Pivotal Tracker is in feature file
# Example: features/course_management/admin_deletes_course.feature
# http://www.pivotaltracker.com/story/show/1423733
@ok
Feature: Admin Deletes Course
  In order to manage course as a resource
  As the admin                            
  I should be able to delete a course    

# Using head and sed to insert story id into commit message
git commit -am "[#`head -n 1 features/course_management/admin_deletes_course.feature | sed 's/.*\///'`] Replacing button ids to confirm to convention."