type_name did not work in Python <= 3.2 due the http://bugs.python.org/issue13577
Bump Vagrant OS version to trusty64

For some unknown reason, 'trusty64' image equals 'precise64' on my
Vagrant, so I switched to 'sincerely/trusty64'.
Merge pull request #37 from pythontutor/vagrant_trusty

Bump Vagrant OS version to trusty64
Rewrite error translations to match Python 3 messages, add tests for it
Merge pull request #38 from pythontutor/errors

Rewrite error translations to match Python 3 messages, add tests for it