Prior to this commit, the run trigger option wouldn't catch for failures outside of the #Subprocess.execute raising exceptions. This commit fixes that by inspecting the exit code result of the subprocess and using the new `exit_codes` option to determine how to move forward with the trigger.
Vagrant Core Plugins
These are plugins that ship with Vagrant. Vagrant core uses its own plugin system to power a lot of the core pieces that ship with Vagrant. Each plugin will have its own README which explains its specific role.