Build GraphQL schemas and execute queries against them

graphql is a package for creating GraphQL servers. Current feature set includes:

• Type-safe schema design
• GraphQL parser in pure OCaml using angstrom (April 2016 RFC draft)
• Query execution
• Introspection of schemas
• Arguments for fields
• Allows variables in queries
• Subscriptions

Supporting packages:

• Use graphql-lwt for Lwt support.
• Use graphql-async for Async support.
• Use graphql-cohttp to run a GraphQL server with cohttp.