Fix #38 - http vs. https connections

As the try to connect to an unsecure api endpoint with user token leads
to an exception we need to adapt our exception handling to print out the
full and correct information.
As `https` connections are industry standard we don't invest much effort
in implementation of the `encryption` feature.
If anybody needs this feature feel free to contribute or file a feature
request where interested can vote on.

Author: cmeissner

phpypam/core/api.py

@@ -27,7 +27,7 @@ def __init__(self, url, app_id, username=None, password=None, token=None, encryp
 
         The costructor collects all data to connect to phpIPAM API. If all data is there it makes the connection to the given server.
 
-        :param url: The URL to a phpIPAM instance. It includes the protocol (`http` or `https`).
+        :param url: The URL to a phpIPAM instance. As phpIPAM expects `https` we also only supports secure connections.
         :type url: str
         :param app_id: The app_id which is used for the API operations.
             For modifying operations it needs read/write access.

phpypam/core/exceptions.py

@@ -39,7 +39,7 @@ def __init__(self, *args, code=None, message=None):
         elif self._code == 500:
             if self._message == 'Invalid username or password':
                 raise PHPyPAMInvalidCredentials(self._message)
-        elif self._code == 400:
+        elif self._code == 400 or self._code == 503:
             raise PHPyPAMInvalidSyntax(message=self._message)
 
         # super(PHPyPAMException, self).__init__(*args, **kwargs)