Error - Removal of Resource Causes Failure Instead of Gracefully Informing User.

[esacci]

Mac dev7.

To recreate - (1) click on resource which itself has a resource dependent, (2) click "-", (3) click 'yes' I'm sure I want to delete the resource.

Cate Desktop, version 2.0.0-dev.7

delete_workspace_resource() call raised exception: "Cannot delete resource "ds_1" because the following resource(s) depend on it: res_2"

An error (code 20) occurred in Cate Core:

Traceback (most recent call last):
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/site-packages/cate/util/web/jsonrpchandler.py", line 192, in send_service_method_result
result = future.result()
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/concurrent/futures/_base.py", line 425, in result
return self.__get_result()
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/concurrent/futures/_base.py", line 384, in __get_result
raise self._exception
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/concurrent/futures/thread.py", line 56, in run
result = self.fn(*self.args, **self.kwargs)
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/site-packages/cate/util/web/jsonrpchandler.py", line 275, in call_service_method
result = method(*method_params)
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/site-packages/cate/webapi/websocket.py", line 269, in delete_workspace_resource
workspace = self.workspace_manager.delete_workspace_resource(base_dir, res_name)
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/site-packages/cate/core/wsmanag.py", line 333, in delete_workspace_resource
workspace.delete_resource(res_name)
File "/Users/edpechorro/cate-2.0.0.dev7/lib/python3.6/site-packages/cate/core/workspace.py", line 435, in delete_resource
'depend on it: %s' % (res_name, ', '.join(dependent_steps)))
cate.core.workspace.WorkspaceError: Cannot delete resource "ds_1" because the following resource(s) depend on it: res_2

[forman]

Should be addressed when fixing #393

[forman]

Closed with #593