Fix Invalid Path Resource error

poc/bin/kapow

@@ -181,7 +181,10 @@ async def get_field(request):
     except KeyError:
         response = web.HTTPNotFound()
     else:
-        content = await connection.get(field)
+        try:
+            content = await connection.get(field)
+        except ValueError:
+            return web.Response(status=400, reason="Invalid Resource Path")
 
         if isinstance(content, StreamReader):
             response = web.StreamResponse(status=200, reason="OK")

spec/test/features/data/handler/error_invalidresource.feature

@@ -10,6 +10,6 @@ Feature: Fail to retrieve an invalid resource for a handler in Kapow! server.
       | method | url_pattern        |
       | GET    | /listRootDir       |
     When I send a request to the testing route "/listRootDir"
-      And I get the resource "invented/path"
+      And I get the resource "/invented/path"
     Then I get 400 as response code
       And I get "Invalid Resource Path" as response reason phrase