run tests with R-travis
add and use function TravisTool
copy
really download to ..
do we need to set PATH? Git-bin is on the PATH
Merge branch 'master' into r-travis-stable

Conflicts:
	appveyor.yml
Merge branch 'r-travis-stable' into r-travis
use travis-tool in sample file
remove native implementations
Merge branch 'r-travis-stable'

Fixes #4 by calling travis-tool.sh.
Merge branch 'r-travis'