Remove unused requires and mixins

src/pane-axis-model.coffee

@@ -1,6 +1,5 @@
 {Model, Sequence} = require 'theorist'
 {flatten} = require 'underscore-plus'
-Delegator = require 'delegato'
 Serializable = require 'serializable'
 
 PaneRow = null
@@ -10,7 +9,6 @@ module.exports =
 class PaneAxisModel extends Model
   atom.deserializers.add(this)
   Serializable.includeInto(this)
-  Delegator.includeInto(this)
 
   constructor: ({@container, @orientation, children}) ->
     @children = Sequence.fromArray(children ? [])

src/pane-axis.coffee

@@ -1,6 +1,4 @@
-Serializable = require 'serializable'
-{$, View} = require './space-pen-extensions'
-PaneAxisModel = require './pane-axis-model'
+{View} = require './space-pen-extensions'
 Pane = null
 
 ### Internal ###

src/pane-container.coffee

@@ -1,5 +1,4 @@
 Serializable = require 'serializable'
-Delegator = require 'delegato'
 {$, View} = require './space-pen-extensions'
 Pane = require './pane'
 PaneContainerModel = require './pane-container-model'
@@ -9,7 +8,6 @@ module.exports =
 class PaneContainer extends View
   atom.deserializers.add(this)
   Serializable.includeInto(this)
-  Delegator.includeInto(this)
 
   @deserialize: (state) ->
     new this(PaneContainerModel.deserialize(state.model))

src/pane-model.coffee

@@ -1,4 +1,4 @@
-{find, compact, clone, extend} = require 'underscore-plus'
+{find, compact, extend} = require 'underscore-plus'
 {dirname} = require 'path'
 {Model, Sequence} = require 'theorist'
 Serializable = require 'serializable'

src/pane.coffee

@@ -3,8 +3,6 @@ Serializable = require 'serializable'
 Delegator = require 'delegato'
 
 PaneModel = require './pane-model'
-PaneRow = require './pane-row'
-PaneColumn = require './pane-column'
 
 # Public: A container which can contains multiple items to be switched between.
 #