Add credentials object to request

PIALibrary/Sources/Core/WebServices/WebServices.swift

@@ -48,5 +48,5 @@ protocol WebServices: class {
     
     func invitesInformation(_ callback: LibraryCallback<InvitesInformation>?)
     
-    func invite(name: String, email: String, _ callback: SuccessLibraryCallback?)
+    func invite(credentials: Credentials, name: String, email: String, _ callback: SuccessLibraryCallback?)
 }

PIALibrary/Sources/Library/Account/DefaultAccountProvider.swift

@@ -283,7 +283,12 @@ class DefaultAccountProvider: AccountProvider, ConfigurationAccess, DatabaseAcce
     }
     
     func invite(name: String, email: String, _ callback: SuccessLibraryCallback?) {
-        webServices.invite(name: name, email: email, { result in 
+
+        guard let user = currentUser else {
+            preconditionFailure()
+        }
+
+        webServices.invite(credentials: user.credentials, name: name, email: email, { result in 
             callback?(result)
         })
     }

PIALibrary/Sources/Library/WebServices/PIAWebServices.swift

@@ -278,17 +278,18 @@ class PIAWebServices: WebServices, ConfigurationAccess {
 
     }
     
-    func invite(name: String, email: String, _ callback: SuccessLibraryCallback?) {
+    func invite(credentials: Credentials, name: String, email: String, _ callback: SuccessLibraryCallback?) {
         let endpoint = ClientEndpoint.invites
-        let status = [200, 400]
+        let status = [200, 400, 401]
         let errors: [Int: ClientError] = [
-            400: .badReceipt
+            400: .badReceipt,
+            401: .unauthorized
         ]
         
         let parameters = ["invitee_name": name,
                           "invitee_email": email]
         
-        req(nil, .post, endpoint, parameters, status, JSONRequestExecutor() { (json, status, error) in
+        req(credentials, .post, endpoint, parameters, status, DataRequestExecutor() { (json, status, error) in
             if let knownError = self.knownError(endpoint, status, errors) {
                 callback?(knownError)
                 return

PIALibrary/Sources/Mock/MockWebServices.swift

@@ -77,7 +77,7 @@ class MockWebServices: WebServices {
         callback?(result, error)
     }
     
-    func invite(name: String, email: String, _ callback: SuccessLibraryCallback?) {
+    func invite(credentials: Credentials, name: String, email: String, _ callback: SuccessLibraryCallback?) {
         callback?(nil)
     }