ADD test for image printing and text

* image printing does not check output
* text test checks output of a very basic string

test/test_load_module.py

@@ -7,6 +7,11 @@
 :license: GNU GPL v3
 """
 
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
 from nose.tools import with_setup
 
 import escpos.printer as printer