Fix typing on StyledSelect

[mdrayer]

Hmm, I think the typing of the options prop/generic could use some help. I was able to use something like

<StyledSelect options={['foo', 'bar']} />

without any type errors in the IDE, but then on the app side:

Unhandled Runtime Error
TypeError: Cannot use 'in' operator to search for 'options' in foo

I think using Option extends DropdownOption instead of Option = DropdownOption in the StyledSelect generics should resolve this. Thoughts?

EDIT: We'd also need this change in the StyledDropdownIndicator generics.

[kmonahan]

Diving back into this and going through React Select's types. The docs imply that the Option generic should extend type OptionType = { [string]: any }, but if I do Option extends OptionType = DropdownOption, I do get the type-checker in my IDE preventing me from setting my options to ['foo', 'bar'], but I can do [{ value: 'foo' }, { value: 'bar' }], in which case all the options show up as blank. So I think you're right -- DropdownOption isn't just the default type for StyledSelect, it's also the minimum type. You need value and label for every option, and we should extend DropdownOption.

[kmonahan]

Updated! Let's see if this works better

[mdrayer]

Looks good!