Switch to Trusty64

Use the current (1.5+) Vagrant Cloud & Boxes 2.0 features to pull in the
base box; make it the official Ubuntu Trusty64 image
account for ruby-switch no longer in Ubuntu base

ruby-switch was removed from Ubuntu base between 12.04 and 14.04; using
a version of ruby installed from a PPA will switch that version to the
system default, so this command is no longer necessary
Merge pull request #1 from DArcMattr/trusty

Trusty