rb: Remove private API instead of deprecating it

The changes going to be released in Selenium 3.0 which may introduce
backwards-incompatibility.

Author: p0deje

rb/lib/selenium/webdriver/chrome/service.rb

@@ -28,11 +28,6 @@ module Chrome
       class Service < WebDriver::Service
         DEFAULT_PORT = 9515
 
-        def self.executable_path
-          warn "Selenium::WebDriver::Chrome::Service.executable_path is deprecated, please use Selenium::WebDriver::Chrome.driver_path instead"
-          Chrome.driver_path
-        end
-
         def self.default_service(*extra_args)
           new Chrome.driver_path, DEFAULT_PORT, *extra_args
         end

rb/lib/selenium/webdriver/edge/service.rb

@@ -28,11 +28,6 @@ module Edge
       class Service
         DEFAULT_PORT = 17556
 
-        def self.executable_path
-          warn "Selenium::WebDriver::Edge::Service.executable_path is deprecated, please use Selenium::WebDriver::Edge.driver_path instead"
-          Edge.driver_path
-        end
-
         def self.default_service(*extra_args)
           new Edge.driver_path, DEFAULT_PORT, *extra_args
         end

rb/lib/selenium/webdriver/firefox/service.rb

@@ -28,11 +28,6 @@ module Firefox
       class Service < WebDriver::Service
         DEFAULT_PORT = 4444
 
-        def self.executable_path
-          warn "Selenium::WebDriver::Firefox::Service.executable_path is deprecated, please use Selenium::WebDriver::Firefox.driver_path instead"
-          Firefox.driver_path
-        end
-
         def self.default_service(*extra_args)
           new Firefox.driver_path, DEFAULT_PORT, *extra_args
         end

rb/lib/selenium/webdriver/phantomjs/service.rb

@@ -28,11 +28,6 @@ module PhantomJS
       class Service < WebDriver::Service
         DEFAULT_PORT = 8910
 
-        def self.executable_path
-          warn "Selenium::WebDriver::PhantomJS::Service.executable_path is deprecated, please use Selenium::WebDriver::PhantomJS.path instead"
-          PhantomJS.path
-        end
-
         def self.default_service(*extra_args)
           new PhantomJS.path, DEFAULT_PORT, *extra_args
         end