Removed deprecated bulk_threshold-instance method

http://www.rubydoc.info/github/rubygems/rubygems/Gem/ConfigFile#bulk_threshold-instance_method
Merge pull request #168 from jeffwidman/patch-1

Removed deprecated bulk_threshold-instance method
Yosemite changed the path of iOS Simulator.app
Update atom and ignore its compile cache
Merge branch 'master' of https://github.com/holman/dotfiles
Add private environment variable loading
Only loading ~/.env-vars file if exists
Merge pull request #172 from eljojo/patch-1

Only loading ~/.env-vars file if exists