Allow to pass a function as parent for <Trans /> component

[rafauke]

Currently if you pass something different than ReactNode to parent prop, propTypes validation throws an error:

Warning: Failed prop type: Invalid prop `parent` supplied to `Trans`, expected a ReactNode.

This would happen if you use glamorousComponent for example.

// RenderedComponent.js

<Trans
  i18nkey='common.myTransKey'
  parent={Text}
  dynamicVal={dynamicVal}
>
  My <strong>interpolation</strong> and this is my <i>{{dynamicVal}}</i>
</Trans>

// Text.js

export const Text = glamorous.p({
  fontSize: 16,
  marginTop: 10
})

[coveralls]

Coverage remained the same at 81.481% when pulling 8a18a3b on rafauke:feature/change-props-validation-for-trans-component into cebdc88 on i18next:master.

[coveralls]

Coverage remained the same at 81.481% when pulling 8a18a3b on rafauke:feature/change-props-validation-for-trans-component into cebdc88 on i18next:master.

[coveralls]

Coverage remained the same at 81.481% when pulling 8a18a3b on rafauke:feature/change-props-validation-for-trans-component into cebdc88 on i18next:master.

[jamuhl]

published in react-i18next@7.6.1