[aws|rds] Allow string or symbol hash keys.

Server#modify and #create_read_replica allow
options to be passed as symbols or strings.

This allows the same hash of attributes to be used
for creating & modifying servers.

For example, the following lines are equivalent:
  server.modify(true, :allocated_storage => 10)
  server.modify(true, 'AllocatedStorage' => 10)

lib/fog/aws/models/rds/server.rb

@@ -25,27 +25,24 @@ module Fog
         attribute :preferred_backup_window, :aliases => 'PreferredBackupWindow'
         attribute :preferred_maintenance_window, :aliases => 'PreferredMaintenanceWindow'
         attribute :db_name, :aliases => 'DBName'
-        attribute :db_security_groups, :aliases => 'DBSecurityGroups'
+        attribute :db_security_groups, :aliases => 'DBSecurityGroups', :type => :array
         attribute :db_parameter_groups, :aliases => 'DBParameterGroups'
         attribute :backup_retention_period, :aliases => 'BackupRetentionPeriod', :type => :integer
         attribute :license_model, :aliases => 'LicenseModel'
 
         attr_accessor :password, :parameter_group_name, :security_group_names, :port
-        
-        def initialize(attributes={})
-          self.flavor_id ||= 'db.m1.small'
-          super
-        end
 
         def create_read_replica(replica_id, options={})
-          connection.create_db_instance_read_replica(replica_id, id, options)
+          options[:security_group_names] ||= options['DBSecurityGroups']
+          params = self.class.new(options).attributes_to_params
+          connection.create_db_instance_read_replica(replica_id, id, params)
           connection.servers.get(replica_id)
         end
-        
+
         def ready?
           state == 'available'
         end
-   
+
         def destroy(snapshot_identifier=nil)
           requires :id
           connection.delete_db_instance(id, snapshot_identifier, snapshot_identifier.nil?)
@@ -56,51 +53,58 @@ module Fog
           connection.reboot_db_instance(id)
           true
         end
-        
+
         def snapshots
           requires :id
           connection.snapshots(:server => self)
         end
-        
+
         def modify(immediately, options)
-          data = connection.modify_db_instance(id, immediately, options)
+          options[:security_group_names] ||= options['DBSecurityGroups']
+          params = self.class.new(options).attributes_to_params
+          data = connection.modify_db_instance(id, immediately, params)
           merge_attributes(data.body['ModifyDBInstanceResult']['DBInstance'])
-          true  
+          true
         end
-        
+
         def save
           requires :engine
           requires :allocated_storage
           requires :master_username
           requires :password
+
+          self.flavor_id ||= 'db.m1.small'
+
+          data = connection.create_db_instance(id, attributes_to_params)
+          merge_attributes(data.body['CreateDBInstanceResult']['DBInstance'])
+          true
+        end
+
+        # Converts attributes to a parameter hash suitable for requests
+        def attributes_to_params
           options = {
             'AllocatedStorage'              => allocated_storage,
             'AutoMinorVersionUpgrade'       => auto_minor_version_upgrade,
             'BackupRetentionPeriod'         => backup_retention_period,
             'DBName'                        => db_name,
-            'DBParameterGroupName'          => parameter_group_name,
+            'DBParameterGroupName'          => parameter_group_name || attributes['DBParameterGroupName'],
             'DBSecurityGroups'              => security_group_names,
             'DBInstanceIdentifier'          => id,
             'AvailabilityZone'              => availability_zone,
             'DBInstanceClass'               => flavor_id,
-            'Port'                          => port,
+            'Port'                          => port || attributes['Port'],
             'Engine'                        => engine,
             'EngineVersion'                 => engine_version,
             'MasterUsername'                => master_username,
-            'MasterUserPassword'            => password,
+            'MasterUserPassword'            => password || attributes['MasterUserPassword'],
             'PreferredMaintenanceWindow'    => preferred_maintenance_window,
             'PreferredBackupWindow'         => preferred_backup_window,
             'MultiAZ'                       => multi_az,
             'LicenseModel'                  => license_model
           }
+
           options.delete_if {|key, value| value.nil?}
-
-
-          data = connection.create_db_instance(id, options)
-          merge_attributes(data.body['CreateDBInstanceResult']['DBInstance'])
-          true
         end
-        
       end
     end
   end

tests/aws/models/rds/server_tests.rb

@@ -6,7 +6,7 @@ Shindo.tests("AWS::RDS | server", ['aws', 'rds']) do
     # We'll need this later; create it early to avoid waiting
     @instance_with_final_snapshot = AWS[:rds].servers.create(rds_default_server_params.merge(:id => uniq_id("fog-snapshot-test"), :backup_retention_period => 1))
 
-    @instance.wait_for { ready? }
+    @instance.wait_for(20*60) { ready? }
 
     tests('#snapshots') do
       snapshot = nil
@@ -51,10 +51,10 @@ Shindo.tests("AWS::RDS | server", ['aws', 'rds']) do
       @instance.reload.wait_for { state == 'rebooting' }
       @instance.reload.wait_for { ready? }
 
-      # Restore back to original state
+      # Restore back to original state using symbols
       restore_options = {
-       'DBParameterGroupName' => orig_parameter_group,
-       'DBSecurityGroups' => orig_security_groups
+       :parameter_group_name => orig_parameter_group,
+       :security_group_names => orig_security_groups
       }
       @instance.modify(true, restore_options)