Manual trigger validation with validateForm does not display errors

### Current Behavior
After executing the `validateForm` method, I don't see any errors

### Expected behavior
After executing the `validateForm` method, form errors should appear

### Reproducible example
Click button "validate form"
https://codesandbox.io/s/formik-validatefieldwithschema-6witd

example from: https://github.com/formium/formik/blob/master/examples/ValidateFieldWithSchema.js

Start with the CodeSandbox reproduction and the referenced examples/ValidateFieldWithSchema.js example, then trace the manual validateForm flow. Confirm the behavior in the form example and determine why validation errors are not displayed; done means clicking “validate form” visibly shows the form errors.

Written by the indexing model from the issue text.