added logic lesson to R Programming
fixed manifest conflicts
tweaked logic lecture
fixed some small typos etc
fix message about dplyr version thanks to @sabaini
tweaked lesson
some minor tweaks thanks to hugo
Trapped possible occurrance of NA in conditional.
Fixing typo
Merge pull request #52 from zhaoy/master

Fixing typo
Fixing typo

"Give it a shot" instead of "Give it shot"
Merge pull request #56 from zhaoy/master

Fixing typo
fix typo per @r-l-parker
Corrects a couple of typographical errors in Count Outcomes, as reported by Alan Bonnici.
Merge branch 'master' of github.com:swirldev/swirl_courses
fix typo per @homemadecroissant
remove ?manip, since it no longer exists in dplyr 0.3
more work on functions
resolved conflicts
changed course type