ignore project & .R files
merge origin/master

Merge branch 'master' of github.com:swirldev/swirl_courses

Conflicts:
	.gitignore
Merge branch 'master' of github.com:swirldev/swirl_courses
Made the custom test example consistent with coursera protocol used in swirl core.
outlining OLS segment for regression models.
Merge remote-tracking branch 'origin/master'
added core courses to course repo
Merge remote-tracking branch 'upstream/master'
update README with popular courses
Mostly notes.
Merge remote-tracking branch 'origin/master'
Adding package dependencies in customTests.R files, mostly for legacy courses.
Added MASS to Regression Models dependencies.
Removing notes etc which clutter swirl menus
Moved package dependencies from customTests.R to dependson.txt
added matrices and data frames lecture
Merge remote-tracking branch 'upstream/master'
fixed hint in matrices and data frames lesson per bill