Add PromiseKit dependency

- Added PromiseKit dependency

Carthage/Checkouts/PromiseKit/Extensions/UIKit/Sources/UIViewController+AnyPromise.h

@@ -0,0 +1,71 @@
+#import <PromiseKit/PromiseKit.h>
+#import <UIKit/UIViewController.h>
+
+/**
+ To import the `UIViewController` category:
+
+    use_frameworks!
+    pod "PromiseKit/UIKit"
+
+ Or `UIKit` is one of the categories imported by the umbrella pod:
+
+    use_frameworks!
+    pod "PromiseKit"
+ 
+ And then in your sources:
+
+    @import PromiseKit;
+*/
+@interface UIViewController (PromiseKit)
+
+/**
+ Presents a view controller modally.
+
+ If the view controller is one of the following:
+
+  - MFMailComposeViewController
+  - MFMessageComposeViewController
+  - UIImagePickerController
+  - SLComposeViewController
+
+ Then PromiseKit presents the view controller returning a promise that is
+ resolved as per the documentation for those classes. Eg. if you present a
+ `UIImagePickerController` the view controller will be presented for you
+ and the returned promise will resolve with the media the user selected.
+
+     [self promiseViewController:[MFMailComposeViewController new] animated:YES completion:nil].then(^{
+         //…
+     });
+
+ Otherwise PromiseKit expects your view controller to implement a
+ `promise` property. This promise will be returned from this method and
+ presentation and dismissal of the presented view controller will be
+ managed for you.
+ 
+     \@interface MyViewController: UIViewController
+     @property (readonly) AnyPromise *promise;
+     @end
+
+     @implementation MyViewController {
+         PMKResolver resolve;
+     }
+ 
+     - (void)viewDidLoad {
+         _promise = [[AnyPromise alloc] initWithResolver:&resolve];
+     }
+ 
+     - (void)later {
+         resolve(@"some fulfilled value");
+     }
+
+     @end
+
+     [self promiseViewController:[MyViewController new] aniamted:YES completion:nil].then(^(id value){
+         // value == @"some fulfilled value"
+     });
+
+ @return A promise that can be resolved by the presented view controller.
+*/
+- (AnyPromise *)promiseViewController:(UIViewController *)vc animated:(BOOL)animated completion:(void (^)(void))block NS_REFINED_FOR_SWIFT;
+
+@end