title: How to resolve nested input types on graphql mutation
body: <p>So I'm having issues trying to resolve a mutation that contains nested input types from another input type, correct me if I'm doing a wrong design with the models.</p>
  
  <p>This is the mutation, I'm using Playground to check it out:</p>
  
  <pre><code>mutation{
    createOrganization(
      name: "Bitas"
      staff: [
        {
          firstName: "Albert"
          lastName: "Chavez"
          position: "Developer"
          contactInformation:[
              {
                  email: "hola@mail.com"
                  phone:"9187631"
                  linkedin: "whatever"
              },
              {
                  email: "hola2@mail.com"
                  phone:"91876312"
                  linkedin: "whatever2"
              }
            ]
          }
      ]
    ){
      name
      staff{
        firstName
        contactInformation{
          email
        }
      }
    }
  }
  </code></pre>
  
  <p>This mutation is creating a relationship between Organization and Employee, which at the same time is creating a relationship between Employee and Contact Information... here are the schemas:</p>
  
  <pre><code>type Organization {
      id: ID!
      name: String!
      staff: [Employee!]!
  }
  
  type Employee {
      id: ID!
      firstName: String!
      lastName: String!
      position: String!
      contactInformation: [ContactInfo!]!
      belongsToOrg: Organization
  }
  
  input employeeInput {
      firstName: String!
      lastName: String!
      position: String!
      contactInformation: [contactInfoInput!]!
      belongsToOrg: ID
  }
  
  type ContactInfo {
      id: ID!
      email: String!
      phone: String!
      linkedin: String!
      belongsTo: Employee!
  }
  
  input contactInfoInput {
      email: String!
      phone: String!
      linkedin: String!
  }
  </code></pre>
  
  <p>Correct me if I'm not creating the mutations correctly</p>
  
  <pre><code>type Mutation {
      createOrganization(name: String!, staff: [employeeInput!]): Organization!
      createEmployee(firstName: String!, lastName: String!, position:String!, contactInformation: [contactInfoInput!]!): Employee!
  }
  </code></pre>
  
  <p>And here are the functions to create: </p>
  
  <pre><code>function createEmployee(parent, args, context, info) {
      return context.prisma.createEmployee({
          firstName: args.firstName,
          lastName: args.lastName,
          position: args.position,
          contactInformation: {
              create: args.contactInformation
          },
      })
  }
  
  function createOrganization(parent, args, context, info) {
      return context.prisma.createOrganization({
          name: args.name,
          staff: {
              create: args.staff
          }
      })
  }
  
  function staff(parent, args, context) {
      return context.prisma.organization({id: parent.id}).staff();
  }
  
  function contactInformation(parent, args, context) {
      return context.prisma.employee({id: parent.id}).contactInformation()
  }
  
  function belongsTo(parent, args, context) {
      return context.prisma.contactInfo({id: parent.id}).belongsTo()
  }
  </code></pre>
  
  <p>So when I hit the mutation on Playground, it gives me the error:</p>
  
  <p><strong>Reason: 'staff.create[0].contactInformation' Expected 'ContactInfoCreateManyWithoutEmployeeInput', found not an object.</strong> </p>
  
  <p>Could please somebody explain me what this means?? Am I not designing correctly the schema or relationships?? Or perhaps is because too many levels of nested inputs??
  If I console.log the contactInformation field on the createOrganization function the value is undefined.</p>
  
  <p>Note: <em>When creating a Employee, the nested mutation works fine.</em></p>
  
  <p>Thanks in advance.</p>