Minor doc fix for ninefold
Remove node.js mention about discouraging specific versions
Add a sentence about encouraging specyfing just minor version
Merge pull request #136 from travis-ci/node-js-remove-discouraged-specific-versions

Remove node.js mention about discouraging specific versions
Revert "Remove blurb about Mac OS capacity"

This reverts commit e555517cc095803c57d45b78c768330d3cbd0f2d.
Merge branch 'gh-pages' of github.com:travis-ci/docs-travis-ci-com into gh-pages
objective-c: update available Xcode SDKs
Added instructions how to use midje for lein2
Merge pull request #137 from mishadoff/clojure-doc

Added instructions how to use midje for lein2
Fix typo
Fix environment variable endpoints
Adding docs for ssh known hosts addon
Merge pull request #139 from travis-ci/db-ssh-known-hosts-docs

Adding docs for ssh known hosts addon
Merge pull request #138 from smcgivern/env_var_endpoints

Fix environment variable endpoints
Add Docker documentation

This commit adds a new page on Docker workers, and adds notes to
various places where use of `sudo` is suggested.

A new CSS class is introduced to draw attention to 'sudo' issue,
but that is, of course, subject to change.
Move Docker doc under /user/workers

Also add the definite article.
Tweak verbiage
Update webhooks setup steps

To reflect GitHub's current navigation
Eschew use of "Docker" in favor of "container"
Standardize on "container-based" instead of "Docker"