Inconsistency between cloud API and emulator API on function calls

[acchou]

Environment details

• OS: MacOSX High Sierra 10.13.4 (17E202)
• Node.js version: v6.11.5
• npm version: 3.10.10
• @google-cloud/functions-emulator version: 1.0.0-beta.4

Steps to reproduce

1. When calling projects.locations.functions.call, the public google cloud function api expects arguments like:

gapi.projects.locations.functions.call({
    name,
    requestBody
})

where requestBody is of type Schema$CallFunctionRequest:

 interface Schema$CallFunctionRequest {
        /**
         * Input to be passed to the function.
         */
        data?: string;
    }

When using the cloud emulator API, the data field only works when it is passed an object, not a string. The live google functions API only allows a string, not an object.