Throw a type error when an attribute is defined on ObjectType which doesn't belong.

[ckarnell]

Graphene gets mad if you put any attributes on an ObjectType besides Arguments, Fields, resolver methods, and class Meta (and maybe some more stuff I don't know about).

Since defining another type of attribute on an ObjectType throws a runtime error, it would be useful if it threw one at compile time as well.

[minznerjosh]

Is this actually true? I know I can define non-resolver methods on an ObjectType, for instance.

I'd be surprised if something like this wasn't allowed:

class MyType(ObjectType):
    my_field = Field(String)  # we need at least one field

    foo_bar = 'baz'  # I bet graphene is fine with this