Add another Ruby version to .travis.yml
Add command option to Guardfile
Don't use deprecated RSpec syntax
Add rspec-collection_matchers gem

RSpec 3 needs it for the `have` matchers.
Remove deprecated RSpec config option
Add acceptance test for typeable passwords

Includes a matcher which checks whether parts of the generated passwords
com from a given list of words.
Make acceptance test use dictionary

Also print more helpful error message if the executable prints an error.
Add unfinished TypeableAlgorithm

Test suite is far from complete.
Put feature spec in pending block

I'll wait until the TypeableAlgorithm is ina decent state before putting
this test online.
WIP test written