Update graphql dependency in gql-format and gql-merge

[amannn]

The specified graphql version in gql-merge and gql-format currently prevents me from upgrading my graphql version, as multiple versions of graphql in node_modules has some issues due to instanceof checks.

I checked the changelog of graphql and it looks like this library shouldn't be affected by breaking changes there.

I tried running your tests, but after lerna bootstrap I got an error: Error: Cannot find module 'gql-utils'. I'm not sure where that issue originates from.

Also flow finds some errors both in the graphql package as well as in your lib code. I added node_modules to your ignored flow files to get rid of the former ones, but I'm not sure where the others are coming from.

Also the lint task returns a bunch of errors – I don't think they are related to the upgrade of graphql, are they?

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Another option would be to remove graphql from dependencies and move them to peerDependencies. WDYT?

[nfantone]

Having similar issue.

IMHO, graphql should definitely be declared as "peerDependency". Having it fixed as an internal dependency can only bring problems down the build pipe line for users.