first stab at an automatically generated module template with create_course()
create_module() now creates a 'my_swirl_courses' directory in the current working directory, within which the authored courses are temporarily stored
made lesson template more complete and changes name of file and function to author_lesson
added roxygen documentation and exported author_lesson() function
Merge pull request #61 from ncarchedi/master

author_lesson() to create swirl content