bug: adapter disconnect

[intech]

moleculer-db-firebase/src/dbServiceMixin.js

Lines 203 to 214 in 24f9aa1

	/**
	* Disconnect from database.
	*
	* @methods
	*
	* @returns {Promise}
	*/
	disconnect() {
	this.adapter.connect();
	return Promise.resolve();
	},

Need adapter.disconnect()? And there is no need to return resolve for all methods.

[Waddah-JD]

thanks for pointing that out!