Connectors Update

• rename HTTP connectors;
• HTTP connectors use only curl, composer package 'fguillot/json-rpc' was removed;
• in HttpJsonRpcConnectorAbstract/WSConnectorAbstract some properties was made static and to constructor added ordering node by timeout answer;
• close old connection before new for WSConnectorAbstract;
• to SteemitHttpJsonRpcConnector were added new nodes (6 total);
• new connector for GOLOS GolosHttpJsonRpcConnector;