title: Problems with updating anaconda and installing new packages
body: <p>I am trying to install seaborn on anaconda on Ubuntu-Linux. </p>
  
  <pre><code>conda install -c anaconda seaborn=0.7.1
  </code></pre>
  
  <p>I am getting the following error message:</p>
  
  <pre><code>Fetching package metadata .../home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/connection.py:337: SubjectAltNameWarning: Certificate for conda.anaconda.org has no `subjectAltName`, falling back to check for a `commonName` for now. This feature is being removed by major browsers and deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 for details.)
    SubjectAltNameWarning
  /home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/connection.py:337: SubjectAltNameWarning: Certificate for conda.anaconda.org has no `subjectAltName`, falling back to check for a `commonName` for now. This feature is being removed by major browsers and deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 for details.)
    SubjectAltNameWarning
  ..An unexpected error has occurred.
  Please consider posting the following information to the
  conda GitHub issue tracker at:
  
      https://github.com/conda/conda/issues
  
  Current conda install:
  
             platform : linux-64
        conda version : 4.2.12
     conda is private : False
    conda-env version : 4.2.12
  conda-build version : 1.19.0
       python version : 3.5.2.final.0
     requests version : 2.12.1
     root environment : /home/moritz/Python/anaconda3  (writable)
  default environment : /home/moritz/Python/anaconda3
     envs directories : /home/moritz/Python/anaconda3/envs
        package cache : /home/moritz/Python/anaconda3/pkgs
         channel URLs : https://repo.continuum.io/pkgs/free/linux-64
                        https://repo.continuum.io/pkgs/free/noarch
                        https://repo.continuum.io/pkgs/pro/linux-64
                        https://repo.continuum.io/pkgs/pro/noarch
          config file : None
         offline mode : False
  </code></pre>
  
  <p>When I run</p>
  
  <pre><code>$ /home/moritz/Python/anaconda3/bin/conda install -c anaconda seaborn=0.7.1
  </code></pre>
  
  <p>I am getting the following error message:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/exceptions.py", line 479, in conda_exception_handler
      return_value = func(*args, **kwargs)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/cli/main.py", line 145, in _main
      exit_code = args.func(args, p)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/cli/main_install.py", line 80, in execute
      install(args, parser, 'install')
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/cli/install.py", line 238, in install
      prefix=prefix)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/api.py", line 24, in get_index
      index = fetch_index(channel_urls, use_cache=use_cache, unknown=unknown)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/fetch.py", line 310, in fetch_index
      repodatas = [(u, f.result()) for u, f in zip(urls, futures)]
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/fetch.py", line 310, in &lt;listcomp&gt;
      repodatas = [(u, f.result()) for u, f in zip(urls, futures)]
    File "/home/moritz/Python/anaconda3/lib/python3.5/concurrent/futures/_base.py", line 398, in result
      return self.__get_result()
    File "/home/moritz/Python/anaconda3/lib/python3.5/concurrent/futures/_base.py", line 357, in __get_result
      raise self._exception
    File "/home/moritz/Python/anaconda3/lib/python3.5/concurrent/futures/thread.py", line 55, in run
      result = self.fn(*self.args, **self.kwargs)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/fetch.py", line 74, in func
      res = f(*args, **kwargs)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/conda/fetch.py", line 116, in fetch_repodata
      timeout=(3.05, 60))
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/sessions.py", line 501, in get
      return self.request('GET', url, **kwargs)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/sessions.py", line 488, in request
      resp = self.send(prep, **send_kwargs)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/sessions.py", line 609, in send
      r = adapter.send(request, **kwargs)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/adapters.py", line 423, in send
      timeout=timeout
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/connectionpool.py", line 594, in urlopen
      chunked=chunked)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/connectionpool.py", line 350, in _make_request
      self._validate_conn(conn)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/connectionpool.py", line 835, in _validate_conn
      conn.connect()
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/connection.py", line 330, in connect
      cert = self.sock.getpeercert()
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/contrib/pyopenssl.py", line 324, in getpeercert
      'subjectAltName': get_subj_alt_name(x509)
    File "/home/moritz/Python/anaconda3/lib/python3.5/site-packages/requests/packages/urllib3/contrib/pyopenssl.py", line 171, in get_subj_alt_name
      ext = cert.extensions.get_extension_for_class(
  AttributeError: 'Extensions' object has no attribute 'get_extension_for_class'`
  </code></pre>
  
  <p>Any idea what the issue could be here? Many thanks in advance.</p>