try to switch ermrest travis build to newer ubuntu beta env.
try to switch ermrest travis build to newer ubuntu beta env.

- Drop deprecated `chkconfig` command
- Add mising `-y` flag on `apt-get` commands
- Symlink missing apache2 `conf.d` to `conf-enabled`
- Revise diagnostic directory listings

informatics-isi-edu/ermrest,informatics-isi-edu/ermrest