Use RootView.eachEditor to attach snippet commands
Use RootView.eachEditor to attach snippet commands

Previously the 'editor:attached' was used which would not
fire for editors already attached and so any editors
opened before the snippets package was loaded would not
have snippets enabled.

lpommers/snippets,terrycloth/atom-snippets,atom/snippets,bengy/snippets,syndbg/snippets