errors from GraphQL requests aren't displayed properly on client (PR available)

[jedwards1211]

Issue - Bug

• OS: OSX / Linux / Windows / ? OSX
• Node version: 5.10.1
• NPM version: 3.9.6
• RethinkDB version: 2.3.0 (CLANG 7.3.0 (clang-703.0.29))

Description

If I try to sign up using an existing email address but different password, the sign up form says "Server query error" at the top. The server prints out an error message:

DEBUG GraphQL Error: [ { [Error: {"_error":"Cannot create account","email":"Email already exists"}]
    originalError: [Error: {"_error":"Cannot create account","email":"Email already exists"}] } ]

Obviously "Email already exists" is intended to be displayed right below the email field in the form, but it's not, nor is the "Cannot create account" message displayed at the top of the form.

Other forms like the Login form similarly fail to display the intended error messages.