libdap Debian package does not install on a plain Ubuntu 14 VM.
I used AWS to make a new Ubuntu 14 image and tried to install the libdap debian package made using Travis (and uploaded here: https://s3.amazonaws.com/opendap.travis.build/libdap_3.20.0-1_amd64.deb).
I used 'sudo apt install ./libdap_3.20.0-1_amd64.deb'. There were a number of errors that looked as though a large number of packages were listed as dependencies.
If the build is broken, switch to using Docker containers.