Added a configuration variable: keep_files (default: ['.git']), based on this pull request: https://github.com/mojombo/jekyll/pull/556
removed puts
use Array.join instead of Array.inject, add .svn to defaults
Changes based on @mojombo's feedback
merge lastest from mojombo/jekyll master
Merge pull request #685 from edeustace/keep_files_feature

Keep files feature
removed extraneous whitespace in test_site.rb
Added Travis CI badge to README
Updated history to reflected merged PRs, #745 and #685.
Updating travis configuration to explicitly run 'rake' behind bundle exec.
Specific patch version of 1.9.3: 362.
Revert "Specific patch version of 1.9.3: 362."

This reverts commit e4517c42af355f31745954c8d133a0461b3e2565.
Merge pull request #750 from mojombo/update-travis-config

Updating travis configuration to explicitly run 'rake' behind bundle exec