Bump min GTMAppAuth to 1.2.3 (#115)

* Bump GTMAppAuth min to 1.2.3 for SPM.

* Bump GTMAppAuth min to 1.2.3 for CocoaPods.

GoogleSignIn.podspec

@@ -33,7 +33,7 @@ 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', '~> 1.5'
-  s.dependency 'GTMAppAuth', '~> 1.0'
+  s.dependency 'GTMAppAuth', '>= 1.2.3', '< 2.0'
   s.dependency 'GTMSessionFetcher/Core', '~> 1.1'
   s.resource_bundle = {
     'GoogleSignIn' => ['GoogleSignIn/Sources/{Resources,Strings}/*']

Package.swift

@@ -40,7 +40,7 @@ let package = Package(
     .package(
       name: "GTMAppAuth",
       url: "https://github.com/google/GTMAppAuth.git",
-      "1.2.0" ..< "2.0.0"),
+      "1.2.3" ..< "2.0.0"),
     .package(
       name: "GTMSessionFetcher",
       url: "https://github.com/google/gtm-session-fetcher.git",