resetForm must be called twice in order to clear values from localstorage

[kaitlynbrown]

Because the componentDidUpdate method uses prevProps instead of this.props, when resetForm is called, it saves the values that existed in the form before resetting. Because of this, I can reset a form, then when I navigate away from it and then back, all the values that were in the form prior to resetting it reappear.

formik-persist/src/formik-persist.tsx

Lines 23 to 27 in 63aeb8f

	componentDidUpdate(prevProps: PersistProps & { formik: FormikProps<any> }) {
	if (!isEqual(prevProps.formik, this.context.formik)) {
	this.saveForm(prevProps.formik);
	}
	}

My current workaround is to simply call resetForm() twice. The second time, redux-persist will correctly save the empty form

[xxczaki]

ping @jaredpalmer