[TravisCI] Add script to update Git repo for Travis

The update-git.sh script is intended to be called by a cron job to
automatically update the Travis CI repository.
Source rvm if we're using it

Needed for the script to work when called by cron.
Update README

Move to Markdown format plus minor edits and updates. Also add build
status image to Travis CI.
Add Travis CI README
Merge branch 'master' of https://github.com/crowbar/crowbar
barclamp install moves to docs to new location
new home for model_barclamp (instead of crowbar barclamp)
staging moving of documentation
add relationship between attribute and barclamp
doc updates
doc updates for BDD testing units