Simplify xterm escape sequences
Use green dots in succinct output of 'lib:find_missing_requires' Rake task
Configure Travis CI to build using 'test' Rake task

Although the default Rake task will gracefully degrade from loading a
debugger, the 'test' Rake task -- added to support the rubygems-test
RubyGem -- is intended to run heedlessly as Travis CI expects.
Document support for newer Ruby versions
Remove outdated mention of upcoming features
Update project history
Bump version number