Clean up trailing whitespaces

Examples/Playground-iOS.playground/section-1.swift

@@ -58,7 +58,7 @@ try! keychain.remove("kishikawakatsumi")
 
 /****************
  * Error handling
-*****************/
+ ****************/
 
 /* set */
 do {

Lib/KeychainAccessTests/KeychainAccessTests.swift

@@ -47,7 +47,7 @@ class KeychainAccessTests: XCTestCase {
     }
 
     // MARK:
-    
+
     func testGenericPassword() {
         do {
             // Add Keychain items