Allow parts of node.travis_build_environment to be overridden
Specify dependent cookbooks for rvm cookbook
add missing metadata.rb files
merge merge merging all the things, thanks @drnic

Merge branch 'metadata' of git://github.com/drnic/travis-cookbooks into drnic-metadata

Conflicts:
	ci_environment/golang/metadata.rb
	ci_environment/libgdbm/metadata.rb
	ci_environment/libncurses/metadata.rb
	ci_environment/libreadline/metadata.rb
	ci_environment/libssl/metadata.rb
	ci_environment/libxml/metadata.rb
	ci_environment/libyaml/metadata.rb
	ci_environment/networking_basic/metadata.rb
	ci_environment/openssh/metadata.rb
	ci_environment/sysctl/metadata.rb
	ci_environment/travis_build_environment/metadata.rb
	ci_environment/unarchivers/metadata.rb
Merge branch 'master' of https://github.com/travis-ci/travis-cookbooks