Remove legacy-data.sql and change tests to use data.sql

legacy-data.sql was moved from cnx-upgrade when to_html.py was moved to
cnx-archive, but it is almost identical to data.sql, so removing it.
Use the correct version in internal links
remove parent path part of resources link: make it a host-relative link
Add "sudo apt-get update" to .travis.yml
Merge pull request #173 from Connexions/fix-version-in-transformation

Fix internal links in transformation