Updated fpdf to the last version (py3 compatible), fix contrib/appconfig

gluon/tests/__init__.py

@@ -10,6 +10,7 @@ from .test_dal import *
 from .test_cache import *
 from .test_template import *
 from .test_html import *
+from .test_contribs import *
 
 if sys.version[:3] == '2.7':
     from .test_compileapp import *
@@ -24,5 +25,4 @@ if sys.version[:3] == '2.7':
     from .test_appadmin import *
     from .test_scheduler import *
     from .test_web import *
-    from .test_contribs import *
     from .test_old_doctests import *

gluon/tests/test_contribs.py

@@ -8,7 +8,7 @@ import os
 from .fix_path import fix_sys_path
 
 fix_sys_path(__file__)
-
+from gluon._compat import to_bytes
 from gluon.storage import Storage
 from gluon.contrib import fpdf as fpdf
 from gluon.contrib import pyfpdf as pyfpdf
@@ -42,8 +42,8 @@ class TestContribs(unittest.TestCase):
         pdf.write(5, 'hello world')
         pdf_out = pdf.output('', 'S')
 
-        self.assertTrue(fpdf.FPDF_VERSION in pdf_out, 'version string')
-        self.assertTrue('hello world' in pdf_out, 'sample message')
+        self.assertTrue(to_bytes(fpdf.FPDF_VERSION) in pdf_out, 'version string')
+        self.assertTrue(to_bytes('hello world') in pdf_out, 'sample message')
 
     def test_appconfig(self):
         """