Add support for Swift Package Manager

[kgn]

I'd like to use this with Vapor which uses Swift Package Manger for dependencies.

[grantkemp]

Hi - its a good idea, but I am not that familiar with with SPM - can you submit a pull request? and we can plan for the release after next?

[kgn]

I wasn't familiar with the steps involved with making a package, but after some reading it seems the only thing that's needed is a Package.swift file and to put all the source files in a Sources directory and move SwiftCSVTests into a Tests directory. However, when I attempted to do this in a fork I ran into compile issues as the code needs to be updated for Swift 3 and there were some things that didn't automatically convert.

Do you plan on updating the library to Swift 3?

Package.swift

import PackageDescription

let package = Package(
    name: "SwiftCSV"
)

[wpuricz]

I would also like to see this as a swift package so that I can use it in Vapor and for command line applications.

[grantkemp]

@kgn we now have a swift 3 version the develop branch. Do you want to try it out and potentially submit SPM fix against that ? and we can release at same time

[kgn]

Finally got around to this: #58

[DivineDominion]

Done in #77