Merge pull request #228 from wbinglee/master

List all instances in a stack
update cl
releasing beta1
releasing 0.8.2
Merge pull request #229 from wbinglee/master

Fix pty option setting in execute command
adding pty option to execute
switching to debug level
Merge pull request #232 from intuit/no_tty

adding pty option to execute
releasing 0.9.0
Updated to include pinned fog-core
Merge pull request #233 from intuit/pin_fog_core

Updated to include pinned fog-core
Updated CHANGELOG for 0.9.1
Skip the stack which is deleted