Add PromiseKit dependency

- Added PromiseKit dependency

Carthage/Checkouts/PromiseKit/Sources/Configuration.swift

@@ -0,0 +1,13 @@
+import Dispatch
+
+/// PromiseKit’s configurable parameters
+public struct PMKConfiguration {
+    /// The default queues that promises handlers dispatch to
+    public var Q: (map: DispatchQueue?, return: DispatchQueue?) = (map: DispatchQueue.main, return: DispatchQueue.main)
+
+    /// The default catch-policy for all `catch` and `resolve`
+    public var catchPolicy = CatchPolicy.allErrorsExceptCancellation
+}
+
+/// Modify this as soon as possible in your application’s lifetime
+public var conf = PMKConfiguration()