Google Code-in

The use case is covered in https://github.com/moremoban/moban/issues/37.

In this task, could you please handle the case where the data file in yaml has syntactical errors, moban could not get data from it.

So this task should provide end user with clearer description on what went wrong and where, so that the end user knows how to debug and solve the exception.

As always, unit tests for the code change are required.

Please also note: the exception case where the yaml file is syntactically correct but missing a few compulsory fields is noted in a separate task.