Version 1.5.0

• Add travis setup rubygems.
• Add travis accounts.
• Add travis monitor.
• Make travis logs stream.
• Add Broadcast entity.
• Add streaming body API.
• Add event listener API.
• Add simple plugin system (will load any ~/.travis/*/init.rb when running cli).
• Implement shell completion for bash and zsh.
• Be smarter about warnings when running travis encrypt.
• Improve documentation.