download course from github version 0.1
download course from github version 0.1.1
Merge remote-tracking branch 'swirldev/master' into install_course

updating my fork
Merge pull request #1 from seankross/install_course

Install course
Added install dropbox and gdrive
added documentation for install_course
Merge remote-tracking branch 'swirldev/master'

bringing install_course to master
compiled documentation
fixed typo
fixed another typo
updated namespace, fixed description
updated roxygen2 to version 3.1.0
install now builds rmd files
removed message(sean)
added uninstall_course
Merge remote-tracking branch 'sean/master' into sean_install
made a few tweaks to install_course... functions
updated help files
made a few tweaks to install_course.R documentation to satisfy R CMD check
a few tweaks to author_lesson.R to prevent user from overwriting existing courses or creating duplicate copies of the same course in different places