Dependency Installation

[atatarenko]

At some point, I realized I was using a pretty outdated version of this lib. The type conversion from JSON::Any didn't work for me but I saw an example where it supposed to work. Anyway, I figured out I can let it run if I point to master in dependencies config like below. There are quite useful commits in the latest master. How about making a release?

dependencies:
  graphql-crystal:
    github: ziprandom/graphql-crystal
    branch: master