Add PromiseKit dependency

- Added PromiseKit dependency

Carthage/Checkouts/PromiseKit/Tests/A+/2.1.3.swift

@@ -0,0 +1,34 @@
+import PromiseKit
+import XCTest
+
+class Test213: XCTestCase {
+    func test() {
+        describe("2.1.3.1: When rejected, a promise: must not transition to any other state.") {
+            testRejected { promise, expectation, _ in
+                promise.test(onFulfilled: { XCTFail() }, onRejected: expectation.fulfill)
+            }
+
+            specify("trying to reject then immediately fulfill") { d, expectation in
+                d.promise.test(onFulfilled: { XCTFail() }, onRejected: expectation.fulfill)
+                d.reject(Error.dummy)
+                d.fulfill()
+            }
+
+            specify("trying to reject then fulfill, delayed") { d, expectation in
+                d.promise.test(onFulfilled: { XCTFail() }, onRejected: expectation.fulfill)
+                after(ticks: 1) {
+                    d.reject(Error.dummy)
+                    d.fulfill()
+                }
+            }
+
+            specify("trying to reject immediately then fulfill delayed") { d, expectation in
+                d.promise.test(onFulfilled: { XCTFail() }, onRejected: expectation.fulfill)
+                d.reject(Error.dummy)
+                after(ticks: 1) {
+                    d.fulfill()
+                }
+            }
+        }
+    }
+}