title: Setting Environmental variable issue
body: <p>I'm getting an auth error with my google api test, the code to set the environmental variable works alone, however when used in conjunction with the google test code the auth fails. I was also able to get the test code to work by running an <code>EXPORT</code> command in shell. For convenience, I'd like to be able to set the auth in my scripts.</p>
  
  <pre><code> #This program will test the google speech api
   #while setting the environmental variable for the
   #authentication .json file and then authenticating
  
   import os
  
   # Imports the Google Cloud client library
   from google.cloud import language
   from google.cloud.language import enums
   from google.cloud.language import types
  
   # My code sets the authentication env variable
   os.environ['GOOGLE_APPLICATION_CREDENTIALS'] = str('home/kyle/Security/test.json')
  
   # Instantiates a client
   client = language.LanguageServiceClient()
  
   # The text to analyze
   text = u'Hello, world!'
   document = types.Document(
       content=text,
       type=enums.Document.Type.PLAIN_TEXT)
  
   # Detects the sentiment of the text
   sentiment = client.analyze_sentiment(document=document).document_sentiment
  
   print('Text: {}'.format(text))
   print('Sentiment: {}, {}'.format(sentiment.score, sentiment.magnitude))
  </code></pre>
  
  <p>The error:</p>
  
  <pre><code>   File "/home/kyle/python projects/googleSpeech/test/venv/lib/python3.5/site-packages/google/auth/_default.py", line 142, in _get_explicit_environ_credentials
  os.environ[environment_vars.CREDENTIALS])
     File "/home/kyle/python projects/googleSpeech/test/venv/lib/python3.5/site-packages/google/auth/_default.py", line 67, in _load_credentials_from_file
  'File {} was not found.'.format(filename))
   google.auth.exceptions.DefaultCredentialsError: File home/kyle/Security/test.json was not found.
  </code></pre>
  
  <p>EDIT now exporting the json file doesnt work I ran this code to test reading the .json file</p>
  
  <pre><code> fd = open(‘/home/kyle/Security/test.json’)
   dat = fd.read()
   fd.close()
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code> SyntaxError: Non-ASCII character '\xe2' in file testRead.py on line 2, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details
  </code></pre>