title: Catching a jira-python exception
body: <p>I am trying to handle jira-python exception but my try, except does not seem to catch it. I also need to add more lines in order to be able to post this. So there they are, the lines.</p>
  
  <pre><code>try:
      new_issue = jira.create_issue(fields=issue_dict)
      stdout.write(str(new_issue.id))
  except jira.exceptions.JIRAError:
      stdout.write("JIRAError")
      exit(1)
  </code></pre>
  
  <p>Here is the code that raises the exception:</p>
  
  <pre><code>import json
  
  
  class JIRAError(Exception):
      """General error raised for all problems in operation of the client."""
      def __init__(self, status_code=None, text=None, url=None):
          self.status_code = status_code
          self.text = text
          self.url = url
  
      def __str__(self):
          if self.text:
              return 'HTTP {0}: "{1}"\n{2}'.format(self.status_code, self.text, self.url)
          else:
              return 'HTTP {0}: {1}'.format(self.status_code, self.url)
  
  
  def raise_on_error(r):
      if r.status_code &gt;= 400:
          error = ''
          if r.text:
              try:
                  response = json.loads(r.text)
                  if 'message' in response:
                      # JIRA 5.1 errors
                      error = response['message']
                  elif 'errorMessages' in response and len(response['errorMessages']) &gt; 0:
                      # JIRA 5.0.x error messages sometimes come wrapped in this array
                      # Sometimes this is present but empty
                      errorMessages = response['errorMessages']
                      if isinstance(errorMessages, (list, tuple)):
                          error = errorMessages[0]
                      else:
                          error = errorMessages
                  elif 'errors' in response and len(response['errors']) &gt; 0:
                      # JIRA 6.x error messages are found in this array.
                      error = response['errors']
                  else:
                      error = r.text
              except ValueError:
                  error = r.text
          raise JIRAError(r.status_code, error, r.url)
  </code></pre>