Ignore cryptography deprecation warnings in DEBUG

It also fixes #158

termius/main.py

@@ -2,9 +2,18 @@
 # -*- coding: utf-8 -*-
 """Entrypoint for CLI tool."""
 import sys
+import os
+import warnings
 from termius.app import TermiusApp
 
 
+if os.getenv('TERMIUS_CLI_DEBUG'):
+    warnings.filterwarnings(
+        'ignore', r'Python 2 is no longer supported by the Python core team. ',
+        UserWarning, r'termius'
+    )
+
+
 def main(argv=None):
     """Process call from terminal."""
     app = TermiusApp()

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py27,py35
+envlist = py27,py36
 skipsdist = True
 
 [testenv]
@@ -15,6 +15,8 @@ commands =
      paver completion_tests
      paver bats
 passenv = SERVERAUDITOR_USERNAME SERVERAUDITOR_PASSWORD
+setenv =
+     TERMIUS_CLI_DEBUG = 1
 
 [flake8]
 exclude = .git*