Merged in rosexceptions-json-NRRPLT-8139 (pull request #120)

[NRRPLT-8139] Fix rospy Exception not being serializable.

Approved-by: Stefano Nardo
Approved-by: Krzysztof Lebioda

hbp_nrp_backend/hbp_nrp_backend/rest_server/__ErrorHandlers.py

@@ -26,7 +26,6 @@ This module contains the error handlers for the REST server.
 For 500 errors, a json object understandable by the HBP
 frontend libraries is returned.
 """
-#from builtins import str
 
 __author__ = 'GeorgHinkel'
 
@@ -88,4 +87,4 @@ def error2json(error):
     logger.exception(error)
     return json.dumps({'message': error.message,
                        'type': error.error_type,
-                       'data': error.data}), error.error_code
+                       'data': str(error.data) if error.data else None}), error.error_code

hbp_nrp_backend/hbp_nrp_backend/rest_server/tests/test_simulation_recorder.py

@@ -81,7 +81,6 @@ class TestSimulationRecorder(RestTest):
         simulations[0].cle.command_simulation_recorder.side_effect = ROSCLEClientException('foo')
         response = self.client.get('/simulation/0/recorder/is-recording')
         self.assertEqual(500, response.status_code)
-        
         self.assertDictEqual(
             json.loads('{"data": null, "message": "foo", "type": "CLE error"}'),
             json.loads(response.data.strip().decode())