Undocumented version 0.4.2 does not work with Node 10

[stevelove]

graphql-validation-complexity/package.json

Line 3 in 3f4164b

"version": "0.4.2",

Hello, thanks for this useful package. I wanted to point out that there does not seem to be a release page associated with the latest 0.4.2 version number. This line appears to break in Node 10.

selectionSet.selections.flatMap is not a function

The breaking change seems to have been introduced in 0.4.0. It would be helpful for others if such changes were documented on the release page.