Merge pull request #38 from kishikawakatsumi/remove

Add removeSharedPassword method :)

Lib/KeychainAccess/Keychain.swift

@@ -576,6 +576,10 @@ public class Keychain {
     
     @availability(iOS, introduced=8.0)
     public func setSharedPassword(password: String, account: String, completion: (error: NSError?) -> () = { e -> () in }) {
+        setSharedPassword(password as String?, account: account, completion: completion)
+    }
+    
+    private func setSharedPassword(password: String?, account: String, completion: (error: NSError?) -> () = { e -> () in }) {
         if let domain = server.host {
             SecAddSharedWebCredential(domain, account, password) { error -> () in
                 if let error = error {
@@ -590,6 +594,11 @@ public class Keychain {
         }
     }
     
+    @availability(iOS, introduced=8.0)
+    public func removeSharedPassword(account: String, completion: (error: NSError?) -> () = { e -> () in }) {
+        setSharedPassword(nil, account: account, completion: completion)
+    }
+    
     @availability(iOS, introduced=8.0)
     public class func requestSharedWebCredential(completion: (credentials: [[String: String]], error: NSError?) -> () = { credentials, error -> () in }) {
         requestSharedWebCredential(domain: nil, account: nil, completion: completion)