Install all dependencies
Don't _build_ vignettes
Also declare cran mirror for install_github
Minor Debian/Ubuntu tweak

One just needs r-base-dev, it pulls in r-base-core.  And one doesn't need the doc packages pulled in by the (meta-)package r-base.
Merge pull request #2 from hadley/patch-1

Install all dependencies
Merge pull request #8 from eddelbuettel/patch-1

Minor Debian/Ubuntu tweak
Use stricter (cran) checking
One more thing to do...
adding an apt-get wrapper
oops
adding a CRAN install step
adding a CRAN install step, typo corrected
simpler approach with explicit loop
Merge pull request #13 from krlmlr/patch-1

One more thing to do...
Merge pull request #11 from hadley/patch-2

Use stricter (cran) checking
Update README.
additional tweaking

using adduser to staff group to write in /usr/local/lib/R/site-library
install just r-base-dev (which implies all the R build needs and more)
install littler which may come in handy for scripting
use chmod for now
a few more changes

- add travis user to group staff to permit sudo-less install.packages() in /usr/local
- generally less sudo use
- devtools install optional
- some reindation as my Emacs config like four spaces :)
Merge branch 'master' of https://github.com/eddelbuettel/r-travis into
merge-dirk

Merged Dirk's changes roughly verbatim, still need to test.

Conflicts:
	scripts/travis-tool.sh