help: fix pager on python 3

fixes:
```
Traceback (most recent call last):
  File "/home/tt/g/atomic/atomic", line 185, in <module>
    sys.exit(_func())
  File "/home/tt/g/atomic/Atomic/help.py", line 57, in help_tty
    pager(result)
  File "/usr/lib64/python3.6/pydoc.py", line 1421, in pager
    pager(text)
  File "/usr/lib64/python3.6/pydoc.py", line 1438, in <lambda>
    return lambda text: pipepager(text, use_pager)
  File "/usr/lib64/python3.6/pydoc.py", line 1468, in pipepager
    pipe.write(text)
TypeError: write() argument must be str, not bytes
```

Signed-off-by: Tomas Tomecek <ttomecek@redhat.com>

Closes: #1128
Approved by: giuseppe

Author: TomasTomecek

Atomic/help.py

@@ -53,7 +53,7 @@ def help_tty(self):
         else:
             # Call the pager
             os.environ['PAGER'] = '/usr/bin/less -R'
-            pager(result)
+            pager(result.decode(self.enc))
 
     def help(self):
         """