remove all remnants of course authoring code
changed goodbye message for test mode
Merge branch 'master' into rm-author
Removed "dev" mode.
Removed courses from package. Added menu which offers to install suggested courses, or to direct user to swirl_courses for manual installation.
A few bug fixes and traps for situations in which the internet is unavailable.
removing cruft
Allow exit from course installation menu.
add some NEWS and increment version number
improved coursera credit prompt and get course id from user
added course repo url to initial course menu
added option to go to course repo in course menu
trivial commit to get travis ci back on track