Add a new style parameter for spinner color when NUXButton is disabled

WordPressAuthenticator.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name          = "WordPressAuthenticator"
-  s.version       = "1.33.0"
+  s.version       = "1.34.0-beta.1"
   s.summary       = "WordPressAuthenticator implements an easy and elegant way to authenticate your WordPress Apps."
 
   s.description   = <<-DESC

WordPressAuthenticator/Authenticator/WordPressAuthenticatorStyles.swift

@@ -39,6 +39,9 @@ public struct WordPressAuthenticatorStyle {
 
     public let disabledTitleColor: UIColor
 
+    /// Color of the spinner that is shown when a button is disabled.
+    public let disabledButtonActivityIndicatorColor: UIColor
+
     /// Style: Text Buttons
     ///
     public let textButtonColor: UIColor
@@ -109,6 +112,7 @@ public struct WordPressAuthenticatorStyle {
                 primaryTitleColor: UIColor,
                 secondaryTitleColor: UIColor,
                 disabledTitleColor: UIColor,
+                disabledButtonActivityIndicatorColor: UIColor,
                 textButtonColor: UIColor,
                 textButtonHighlightColor: UIColor,
                 instructionColor: UIColor,
@@ -139,6 +143,7 @@ public struct WordPressAuthenticatorStyle {
         self.primaryTitleColor = primaryTitleColor
         self.secondaryTitleColor = secondaryTitleColor
         self.disabledTitleColor = disabledTitleColor
+        self.disabledButtonActivityIndicatorColor = disabledButtonActivityIndicatorColor
         self.textButtonColor = textButtonColor
         self.textButtonHighlightColor = textButtonHighlightColor
         self.instructionColor = instructionColor

WordPressAuthenticator/NUX/NUXButton.swift

@@ -12,7 +12,7 @@ import WordPressKit
     open override var isEnabled: Bool {
         didSet {
             if #available(iOS 13, *) {
-                activityIndicator.color = isEnabled ? style.primaryTitleColor : style.secondaryTitleColor
+                activityIndicator.color = isEnabled ? style.primaryTitleColor : style.disabledButtonActivityIndicatorColor
             }
         }
     }

WordPressAuthenticatorTests/Mocks/WordpressAuthenticatorProvider.swift

@@ -32,6 +32,7 @@ public class WordpressAuthenticatorProvider: NSObject {
                 primaryTitleColor: UIColor.random(),
                 secondaryTitleColor: UIColor.random(),
                 disabledTitleColor: UIColor.random(),
+                disabledButtonActivityIndicatorColor: UIColor.random(),
                 textButtonColor: UIColor.random(),
                 textButtonHighlightColor: UIColor.random(),
                 instructionColor: UIColor.random(),