few changes based on MR feedback

lib/gitlab/import_export/project_tree_saver.rb

@@ -22,7 +22,7 @@ module Gitlab
       private
 
       def project_json_tree
-        @project.to_json(Gitlab::ImportExport::ImportExportReader.new(shared: @shared).project_tree)
+        @project.to_json(Gitlab::ImportExport::Reader.new(shared: @shared).project_tree)
       end
     end
   end

lib/gitlab/import_export/import_export_reader.rb → lib/gitlab/import_export/reader.rb

 module Gitlab
   module ImportExport
-    class ImportExportReader
+    class Reader
 
       def initialize(shared:)
         @shared = shared

spec/lib/gitlab/import_export/import_export_reader_spec.rb → spec/lib/gitlab/import_export/reader_spec.rb

 require 'spec_helper'
 
-describe Gitlab::ImportExport::ImportExportReader, lib: true  do
+describe Gitlab::ImportExport::Reader, lib: true  do
   let(:shared) { Gitlab::ImportExport::Shared.new(relative_path:'') }
   let(:test_config) { 'spec/support/import_export/import_export.yml' }
   let(:project_tree_hash) do