title: Pyhdfs copy_from_local causing nodename nor servname provided, or not known error
body: <p>I am using the following python code to upload a file to remote HDFS from my local system using <code>pyhdfs</code> </p>
  
  <pre><code>from pyhdfs import HdfsClient
  client = HdfsClient(hosts='1.1.1.1',user_name='root')
  client.mkdirs('/jarvis')
  client.copy_from_local('/my/local/file,'/hdfs/path')
  </code></pre>
  
  <p>Using python3.5/.
  Hadoop is running in default port : 50070
  1.1.1.1 is my remote Hadoop url</p>
  
  <p>Creating dir "jarvis" is working fine, but copying a file is not working. I am getting the following error </p>
  
  <blockquote>
    <p>Traceback (most recent call last):<br>
      File "test_hdfs_upload.py", line 14, in 
        client.copy_from_local('/tmp/data.json','/test.json')<br>
      File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pyhdfs.py", line 753, in copy_from_local
        self.create(dest, f, **kwargs)<br>
      File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pyhdfs.py", line 426, in create
        metadata_response.headers['location'], data=data, **self._requests_kwargs)<br>
      File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/requests/api.py", line 99, in put
        return request('put', url, data=data, **kwargs)<br>
      File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/requests/api.py", line 44, in request
        return session.request(method=method, url=url, **kwargs)<br>
      File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/requests/sessions.py", line 383, in request
        resp = self.send(prep, **send_kwargs)<br>
      File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/requests/sessions.py", line 486, in send
        r = adapter.send(request, **kwargs)<br>
      File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/requests/adapters.py", line 378, in send
        raise ConnectionError(e)
    requests.exceptions.ConnectionError: HTTPConnectionPool(host='ip-1-1-1-1', port=50075): Max retries exceeded with url: /webhdfs/v1/test.json?op=CREATE&amp;user.name=root&amp;namenoderpcaddress=ip-1-1-1-1:9000&amp;overwrite=false (Caused by : [Errno 8] nodename nor servname provided, or not known) </p>
  </blockquote>