refactor(extensions): Move extensions outside of flux/ folder

Not really related to flux, makes more sense to be inside src/

spec/stores/draft-store-spec.coffee

@@ -6,7 +6,7 @@ ModelQuery = require '../../src/flux/models/query'
 AccountStore = require '../../src/flux/stores/account-store'
 DatabaseStore = require '../../src/flux/stores/database-store'
 DraftStore = require '../../src/flux/stores/draft-store'
-ComposerExtension = require '../../flux/src/extensions/composer-extension'
+ComposerExtension = require '../../src/extensions/composer-extension'
 SendDraftTask = require '../../src/flux/tasks/send-draft'
 DestroyDraftTask = require '../../src/flux/tasks/destroy-draft'
 SoundRegistry = require '../../src/sound-registry'

src/extension-registry.es6

@@ -55,7 +55,7 @@ Registry.include(Listener);
 
 export const Composer = new Registry(
   'Composer',
-  require('./flux/extensions/composer-extension-adapter')
+  require('./extensions/composer-extension-adapter')
 );
 
 export const MessageView = new Registry(

src/extensions/composer-extension-adapter.coffee

@@ -1,6 +1,6 @@
 _ = require 'underscore'
-{deprecate} = require '../../deprecate-utils'
-DOMUtils = require '../../dom-utils'
+{deprecate} = require '../deprecate-utils'
+DOMUtils = require '../dom-utils'
 
 ComposerExtensionAdapter = (extension) ->
 

src/global/nylas-exports.coffee

@@ -133,9 +133,9 @@ class NylasExports
 
   # Extensions
   @require "ExtensionRegistry", 'extension-registry'
-  @require "ContenteditableExtension", 'flux/extensions/contenteditable-extension'
-  @require "ComposerExtension", 'flux/extensions/composer-extension'
-  @require "MessageViewExtension", 'flux/extensions/message-view-extension'
+  @require "ContenteditableExtension", 'extensions/contenteditable-extension'
+  @require "ComposerExtension", 'extensions/composer-extension'
+  @require "MessageViewExtension", 'extensions/message-view-extension'
 
   # React Components
   @get "React", -> require 'react' # Our version of React for 3rd party use