Add SwiftFormat to the project. (#129)

* Run swiftformat for whitespace.
* Run swiftformat with some rules.

UnitTests/Sources/UserIndicators/UserIndicatorQueueTests.swift

@@ -1,4 +1,4 @@
-// 
+//
 // Copyright 2021 New Vector Ltd
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -14,9 +14,9 @@
 // limitations under the License.
 //
 
+@testable import ElementX
 import Foundation
 import XCTest
-@testable import ElementX
 
 class UserIndicatorQueueTests: XCTestCase {
     var indicators: [UserIndicator]!
@@ -28,7 +28,7 @@ class UserIndicatorQueueTests: XCTestCase {
     }
     
     func makeRequest() -> UserIndicatorRequest {
-        return UserIndicatorRequest(
+        UserIndicatorRequest(
             presenter: UserIndicatorPresenterSpy(),
             dismissal: .manual
         )