replace find_element_by_name with accessibility id
replace find_element_by_name with accessibility id

* fix bug

* change find element method to by_accessibility_id

* reset ios platform version

ralfleonir/sample-code,appium/sample-code,ralfleonir/sample-code,appium/sample-code,TikhomirovSergey/sample-code,TikhomirovSergey/sample-code,ralfleonir/sample-code,appium/sample-code,TikhomirovSergey/sample-code,TikhomirovSergey/sample-code,TikhomirovSergey/sample-code,TikhomirovSergey/sample-code,ralfleonir/sample-code,ralfleonir/sample-code,appium/sample-code,appium/sample-code,appium/sample-code,ralfleonir/sample-code,TikhomirovSergey/sample-code,ralfleonir/sample-code,appium/sample-code,ralfleonir/sample-code,appium/sample-code,TikhomirovSergey/sample-code