Install apm into node_modules

settings-views launches apm via a NodeBufferedProcess so it still needs to
be available built against Atom's headers.

The version in apm/ is just for running via the CLI directly and is compiled
against node's headers.

src/package-manager.coffee

@@ -39,7 +39,7 @@ class PackageManager
 
   # Public: Get the path to the apm command
   getApmPath: ->
-    @apmPath ?= require.resolve('../apm/node_modules/atom-package-manager/bin/apm')
+    @apmPath ?= require.resolve('atom-package-manager/bin/apm')
 
   # Public: Get the paths being used to look for packages.
   #