Apollo-client: Update to include typescript 1.8 features

[jbaxleyiii]

'll do the update and list out the new features that are meaningful here. :+1:

_Note_
We have been using 1.8, but typescript just updated their site and have a good breakdown of 1.8 features. A few of them will be helpful here so I'll document them as tooling enhancements and open a corresponding PR with the adjustments

[mquandalle]

Aren’t we using typescript 1.8.9 already? https://github.com/apollostack/apollo-client/blob/048ac76b7c9f7399db3e788cb8ceca6091d01e91/package.json#L47

[mquandalle]

Oh, did you mean update to TS 1.8 new language features?

[jbaxleyiii]

@mquandalle yep! Wherever they can be applied!

[mquandalle]

Maybe one occurrence of that is in the GraphQL .d.ts interface definition, I think the following interfaces could be modified as follows:

    interface IntValue {
-       kind: string;
+       kind: "IntValue";
        loc?: Location;
        value: string;
    }

    interface FloatValue {
-       kind: string;
+       kind: "FloatValue";
        loc?: Location;
        value: string;
    }

[stubailo]

ooh, that's neat. we should send a PR or something? or do these definitions want to be compatible with multiple versions of the language?

[jbaxleyiii]

closing because it looks like we are already using everything useful