remove unused variables and duplicate keys

tests/helpers/mock_helper.rb

@@ -97,7 +97,6 @@ if Fog.mock?
     :vsphere_username                 => 'apiuser',
     :vsphere_password                 => 'apipassword',
     :vsphere_expected_pubkey_hash     => 'abcdef1234567890',
-    :libvirt_uri                      => 'qemu:///system',
     :libvirt_username                 => 'root',
     :libvirt_password                 => 'password',
     :cloudsigma_username              => 'csuname',

tests/requests/dns/change_resource_record_sets_tests.rb

@@ -1,6 +1,4 @@
 Shindo.tests('Fog::DNS[:aws] | change_resource_record_sets', ['aws', 'dns']) do
-  @r53_connection = Fog::DNS[:aws]
-
   tests('success') do
     test('#elb_hosted_zone_mapping from DNS name') do
       zone_id = Fog::DNS::AWS.hosted_zone_for_alias_target('arbitrary-sub-domain.eu-west-1.elb.amazonaws.com')

tests/requests/emr/helper.rb

@@ -157,7 +157,6 @@ class AWS
             }],
             'MasterInstanceType' => String,
             'SlaveInstanceType' => String,
-            'InstanceGroups' => Array,
             'TerminationProtected' => String,
             'HadoopVersion' => String
           }