Updated libgraphqlparser to include schema parsing

[schloerke]

Hi @jeroenooms,

Could you update to the latest libgraphqlparser?

It now includes schema parsing. Yay!

(Major feature pull request that was merged in graphql/libgraphqlparser#45)

Thank you,
Barret

[schloerke]

Is there a way to do this on my own to not bother you? I do not need any of this on cran for a while but do enjoy using your c wrapper to the parser. I'd be happy to update a local copy, but I can't figure out which files you're copying.

[jeroen]

Sure just run cmake in the libgraphqlparser repo and copy the src files into the r pkg

[jeroen]

I have updated libgraphqlparser code: 18e76b9. Do we need to write additional bindings to support schema parsing or is that covered by the existing graphql2json?

[schloerke]

Added support for the schema here: #6

This should cover schema parsing bindings.