Backticks in input GraphQL schema file break resolver output

[danielfinke]

If you use backticks in an input GraphQL schema file, such as in the following field and type descriptions,

# Comment test with "double quotes" and 'single quotes'

"Members of `Group`s"
type User {
  firstName: String
  lastName: String
  "Computed based on `firstName` and `lastName`"
  fullName: String
}

"Description test with 'single quotes'"
type Group {
  name: String
}

the output of schemaDataModelJSON in the resolver output will be badly formed and the module will break.

Backticks in comments are fine because they are already stripped from the schema. The example above includes other JS string delimiters to account for in the fix.

Command: node ./neptune-for-graphql.js --input-schema-file test.graphql --output-no-lambda-zip