Bump min AppAuth to 1.5 for macOS support (#109)

* Bump podspec min AppAuth to 1.5

* Bump SPM min AppAuth to 1.5

GoogleSignIn.podspec

@@ -32,7 +32,7 @@ The Google Sign-In SDK allows users to sign in with their Google account from th
   ]
   s.ios.framework = 'UIKit'
   s.osx.framework = 'AppKit'
-  s.dependency 'AppAuth', '~> 1.4'
+  s.dependency 'AppAuth', '~> 1.5'
   s.dependency 'GTMAppAuth', '~> 1.0'
   s.dependency 'GTMSessionFetcher/Core', '~> 1.1'
   s.resource_bundle = {

Package.swift

@@ -36,7 +36,7 @@ let package = Package(
     .package(
       name: "AppAuth",
       url: "https://github.com/openid/AppAuth-iOS.git",
-      "1.4.0" ..< "2.0.0"),
+      "1.5.0" ..< "2.0.0"),
     .package(
       name: "GTMAppAuth",
       url: "https://github.com/google/GTMAppAuth.git",