GraphQL import throws

When importing other .graphql files from schema.graphql, building the server fails.

Minimal example in Codesandbox: https://codesandbox.io/s/q848mq9o1w

schema.graphql:
```graphql
# import Post from "posts.graphql"

type Query {
posts: [Post]
}
```
posts.graphql:
```graphql
type Post {
id: ID!
text: String!
tags: [String]
}
```

Output on the terminal:

I tried with v1.0.2 up to 1.0.8, also with "./posts.graphql", but without success. Any idea?