Merge pull request #6 from beanumber/clean

lab0 renders to HTML be default
Update and rename to-do.md to labSourceStyleGuide.md

rename and move to-do to "issues" on GitHub
update css fonts
small changes
resolving merge conflict
Merge branch 'naomilong-master'
add lab5 markdown
conform style of lab0
second read through corrections
removed redundant reference to data.frame in subset() command