fix: flow types for Validation

Author: jedwards1211

src/Validation.js.flow

@@ -1,11 +1,10 @@
 // @flow
 
 import Type from './types/Type'
+import RuntimeTypeErrorItem from './errorReporting/RuntimeTypeErrorItem'
 
 export type IdentifierPath = Array<string | number | symbol>
 
-export type RuntimeTypeErrorItem = [IdentifierPath, string, Type<any>]
-
 declare class Validation {
   input: any;
 

src/typeConstraints.js.flow

@@ -1,10 +1,7 @@
 // @flow
 
 import Type from './types/Type'
-import Validation, {
-  type RuntimeTypeErrorItem,
-  type IdentifierPath,
-} from './Validation'
+import Validation, { type IdentifierPath } from './Validation'
 
 export type TypeConstraint<T> = (input: T) => ?string