Add a test for backed-up file

Author: hico-horiuchi

spec/integration/default_spec.rb

@@ -55,6 +55,11 @@
   it { should be_directory }
 end
 
+describe command('cat /var/itamae/backup/tmp/file.itamae-*') do
+  its(:stdout) { should match(/Hello World/) }
+  its(:exit_status) { should eq(0) }
+end
+
 describe file('/tmp/file') do
   it { should be_file }
   its(:content) { should match(/Hello New World/) }