Swift 3 support - #194

@ikesyo is this updated to the latest beta?

Hi @ikesyo, shouldn't we rename interceptURLRequest and interceptObject too like you did responseFromObject?
what about change enum cases to lowercase too maybe?
I would love to help! if there is anything i can do!

the Xcode 8 is out, can we merge this @ikesyo @ishkawa?

@ikesyo Thank you for the great work 👍 👍 👍

I have some suggestions that would improve smoothness with Swift 3 APIs.

Omit Type suffix of some protocols

According to the API Design Guidelines, "Protocols that describe what something is should read as nouns (e.g. Collection)." RequestType, BodyParametersType, DataParserType and SessionAdapterType seem to satisfy this condition.

Rename sendRequest(_:handler:) to send(_:handler:)

IMO, the word "request" can be omitted because it is implied when we send something from Session.

Rename cancelRequest(_:passingTest:) to cancelRequests(withType:passingTest:)

Unlike the sending method, canceling method treats multiple requests. I think we should imply we may cancel multiple requests, so the word "requests" should be exposed in method name. In addition, withType label is necessary because the type of the first parameter is not explicit in this context.

After we resolve renaming, I will merge this PR and initial beta of 3.0 ✨

The renaming is finished. ✨

🎉