adds couple of tests for graphql.FieldResolveFn - #44
adds couple of tests for graphql.FieldResolveFn - #44

adds query and mutation test to check correct returning error from graphql.FieldResolveFn

sogko/graphql,kr15h/graphql,sogko/graphql-go,equinux/graphql,housinganywhere/graphql,SpruceHealth/graphql,graphql-go/graphql