save new Lesson as initial commit; updated checkin/checkout mechanism in edit_lesson()
save new Lesson as initial commit; updated checkin/checkout mechanism in edit_lesson()

raccoongang/socraticqs2,raccoongang/socraticqs2,cjlee112/socraticqs2,cjlee112/socraticqs2,derdmitry/socraticqs2,raccoongang/socraticqs2,raccoongang/socraticqs2,derdmitry/socraticqs2,derdmitry/socraticqs2,cjlee112/socraticqs2,cjlee112/socraticqs2