`nef` testing

[miguelangel-dev]

Description

Add testing support to nef to reduce the boilerplate for using XCTests (or any third party library).

Example of use

we could add to our Swift Playground something like:

import XCTest

class ExampleTests: XCTestCase {

    func testHelloWorld_Success() {
        let helloWorld = "Hello World!"
        XCTAssertEqual(helloWorld, "Hello World!")
    }

    func testHelloWorld_Failure() {
        let helloWorld = "Hello World!"
        XCTAssertEqual(helloWorld, "Hello World! - Failure")
    }
}

and launch this TestCase using nef as follow:

Nef.run(testCase: ExampleTests.self)

in this example, the output will be:

As you can see, test failures and final state for test suit is remarked.