Remove Selected Disables Options

[asalem1]

This issue is similar to #109 but not entirely the same. The issue I'm encountering is that by passing removeSelected={false} as a prop (as per the documentation), the options remain, however none of the other group options are selectable. That is, that once you've selected an option from a group (with removeSelected set to false), the group options appear, but can no longer be selected. Therefore, in the case an individual wants to select multiple options from a subgroup, the functionality does not exist for it. To replicate the issue:

<Select
  multi
  noResultsText="Sorry, your request is invalid"
  onChange={this.handleChange}
  onValueClick={() => this.onValueClick()}
  options={options}
  value={selectedOption}
  removeSelected={false}
/>