Change new occurrencies of n1-default-4

app/models/clusters/providers/gcp.rb

@@ -7,7 +7,7 @@ module Clusters
 
       default_value_for :zone, 'us-central1-a'
       default_value_for :num_nodes, 3
-      default_value_for :machine_type, 'n1-standard-4'
+      default_value_for :machine_type, 'n1-standard-2'
 
       attr_encrypted :access_token,
         mode: :per_attribute_iv,

spec/models/clusters/providers/gcp_spec.rb

@@ -10,7 +10,7 @@ describe Clusters::Providers::Gcp do
     it "has default value" do
       expect(gcp.zone).to eq('us-central1-a')
       expect(gcp.num_nodes).to eq(3)
-      expect(gcp.machine_type).to eq('n1-standard-4')
+      expect(gcp.machine_type).to eq('n1-standard-2')
     end
   end