#392 Error in ReaderError __str__()

[MTU]

There is an error in the ReaderError class.
https://sourceforge.net/p/ruamel-yaml/code/ci/default/tree/reader.py#l59
It should be "self_reason" instead of "self.reason"

A KeyError is raised during the string formatting.

Thanks.

[Anthon van der Neut]

This should be fixed in 0.17.11