added method for calculating # tutors for course on model
updated course show page
Removed edit page for courses, as you can update directly from the show page
updated course controller tests
Merge branch 'integration' into feature/37+41-course_tutor_number

Conflicts:
	app/models/course.rb
	db/schema.rb
Merge pull request #18 from aspett/feature/37+41-course_tutor_number

Feature/37+41 course tutor number