GraphQLError is unhashable

[andrew-humu]

It seems that the logging library in python assumes that exceptions are hashable, in order to be logged. It'd be great if we could treat GraphQL errors the same way as other builtin exceptions.

See also, a similar issue in the schematics project:

schematics/schematics#452

[Cito]

Thank you for reporting this. The problem is that GraphQLError implements __eq__ which causes it to lose the default hash capability as Exception. I agree this should be fixed (see #35 for implementation details).