title: fabric2 using a private key
body: <p>So i have this little script : </p>
  
  <pre><code>#!/usr/bin/env python
  #-*- coding: utf-8 -*-
  
  from fabric2 import Connection
  
  c = Connection('192.168.1.666',connect_kwargs={"key_filename": "privatekey"})
  
  
  c.local('touch test3.txt')
  
  
  #with c.cd('/home/gaiman/productmicro'):
      #c.run('git pull origin master')
  
  with c.cd('/home/gaiman/productmicro'):
      c.run('touch test4.txt')
  </code></pre>
  
  <p>The problem is that i have a problem with the privatekey : </p>
  
  <pre><code>  File "/usr/local/lib/python3.6/dist-packages/paramiko/pkey.py", line 289, in _read_private_key
      raise SSHException("not a valid " + tag + " private key file")
  paramiko.ssh_exception.SSHException: not a valid RSA private key file
  </code></pre>
  
  <p>The private key is in the same folder of the script however.</p>
  
  <p>I don't understand</p>