Updates the tests work on ruby-1.9.3 and JRuby

spec/googleauth/compute_engine_spec.rb

@@ -44,7 +44,8 @@ describe Google::Auth::GCECredentials do
     @client = GCECredentials.new
   end
 
-  def make_auth_stubs(access_token: '')
+  def make_auth_stubs(opts = {})
+    access_token = opts[:access_token] || ''
     Faraday::Adapter::Test::Stubs.new do |stub|
       stub.get(MD_URI) do |env|
         headers = env[:request_headers]

spec/googleauth/service_account_spec.rb

@@ -50,7 +50,8 @@ describe Google::Auth::ServiceAccountCredentials do
         StringIO.new(cred_json_text))
   end
 
-  def make_auth_stubs(access_token: '')
+  def make_auth_stubs(opts = {})
+    access_token = opts[:access_token] || ''
     Faraday::Adapter::Test::Stubs.new do |stub|
       stub.post('/oauth2/v3/token') do |env|
         params = Addressable::URI.form_unencode(env[:body])

spec/googleauth/signet_spec.rb

@@ -49,7 +49,8 @@ describe Signet::OAuth2::Client do
       )
   end
 
-  def make_auth_stubs(access_token: '')
+  def make_auth_stubs(opts)
+    access_token = opts[:access_token] || ''
     Faraday::Adapter::Test::Stubs.new do |stub|
       stub.post('/o/oauth2/token') do |env|
         params = Addressable::URI.form_unencode(env[:body])