Create an example Xcode project file to include in 'hello world' exercise

[chillpop]

Per this comment: exercism/exercism#2401 (comment) and the discussion below, we should create an example Xcode project for running tests.

Also include an empty solution file (HellowWorld.h/m) for 'hello world' that is included in the sample Xcode project.

[chillpop]

After this is complete, the relevant section of WORKFLOW.md should be updated too.

[RichardBronosky]

@chillpop How is this for an example? https://dl.dropboxusercontent.com/u/310759/u/ExercismObjectiveCExampleProject.tgz I added a setup.sh script that is pretty self explanatory and gives instructions if you run it incorrectly.

For your second request, http://exercism.io/languages/objective-c#tests has been updated to reflect ae27842 which is clear, though tedious. Would you agree?

[chillpop]

The idea was to include an example Xcode project with the initial "Hello World" test. See how the swift track has done it for an example: https://github.com/exercism/xswift/tree/master/hello-world

[masters3d]

What do you think about adopting Xcode's built in (SPM) Swift Package Manager to build this project file? See the sample formatting here:
https://github.com/masters3d/SwiftPackageManagerSamples/tree/master/ObjC-PackageAcronym

We could introduce the SPM folder structure for each exercise. The objective-c project can be generated by swift package generate-xcodeproj inside each exercise.

This will still help new comers get started faster with objective-c and xcode.

CC @robtimp

[masters3d]

With this PR accepted we can now run tests from the command line
swiftlang/swift-package-manager#850

Adopting SPM folder structure to distribute exercises makes more sence once that stars shipping in xcode.

We will first adopt SPM in Swift then add it to Obj-c. Please let me know if there are any concerns.

[mindejulian]

@masters3d I had not seen this, but I do like the idea. I use the ruby objc gem myself, just so I don't have to set up Xcode projects for every task. However, if it was as simple as it seems here it sounds like a great plan!