Add "types" field to package.json

[cprecioso]

The types field in package.json allows TypeScript 2 to automatically use the type declaration without needing to install it specifically through the typings tool.

More info: https://github.com/Microsoft/TypeScript-Handbook/blob/master/pages/declaration%20files/Publishing.md

[coveralls]

Coverage remained the same at 95.958% when pulling 1efaab8 on cprecioso:patch-1 into eabc218 on blakeembrey:master.

[blakeembrey]

#75

[cprecioso]

I don't understand what the problems you describe in #75 are. I patched the popsicle package.json in my project and TypeScript detected it right away, without any problems.

[blakeembrey]

@cprecioso You may also be interested in knowing that isn't a new TypeScript feature. It's existed for a couple of years since 1.5 was released. The reason I don't use it here and in other modules is because of dependencies. TypeScript 2.0 improves that situation by using NPM for dependencies (@types), but they don't support the dependencies I use yet because they haven't implemented redirects yet. See microsoft/types-publisher#4.

[blakeembrey]

I see two imports in the emitted .d.ts files, one for tough-cookie and one for form-data which should be creating type errors in TypeScript because the definitions don't exist natively (currently come from Typings). Did you not run into that somehow?

[cprecioso]

I did run into that, but my build system ate those errors it seems. Ok, thanks!