default singleTrailingNewline to true

src/packages/whitespace/lib/whitespace.coffee

@@ -2,6 +2,9 @@ module.exports =
   activate: ->
     rootView.eachBuffer (buffer) => @whitespaceBeforeSave(buffer)
 
+  configDefaults:
+    singleTrailingNewline: true
+
   whitespaceBeforeSave: (buffer) ->
     buffer.on 'will-be-saved', ->
       buffer.transact ->

src/packages/whitespace/spec/whitespace-spec.coffee

@@ -21,6 +21,9 @@ describe "Whitespace", ->
   it "strips trailing whitespace before an editor saves a buffer", ->
     spyOn(fs, 'write')
 
+    config.set("whitespace.ensureSingleTrailingNewline", false)
+    config.update()
+
     # works for buffers that are already open when extension is initialized
     editor.insertText("foo   \nbar\t   \n\nbaz")
     editor.getBuffer().save()