Deactivate RootView before removing files.

To limit the amount of fs events that are triggered.

src/extensions/tree-view/spec/tree-view-spec.coffee

@@ -22,7 +22,7 @@ describe "TreeView", ->
     expect(treeView.root.directory.subscriptionCount()).toBeGreaterThan 0
 
   afterEach ->
-    rootView.deactivate()
+    rootView?.deactivate()
 
   describe ".initialize(project)", ->
     it "renders the root of the project and its contents alphabetically with subdirectories first in a collapsed state", ->
@@ -596,6 +596,8 @@ describe "TreeView", ->
       fileView = treeView.find('.file:contains(test-file.txt)').view()
 
     afterEach ->
+      rootView.deactivate()
+      rootView = null
       fs.remove(rootDirPath) if fs.exists(rootDirPath)
 
     describe "tree-view:add", ->