Remove Selenium 2 references (Using Selenium 3 now)

Author: mdmintz

help_docs/mysql_installation.md

@@ -29,12 +29,6 @@ If you want a visual tool to help make your MySQL life easier, [try MySQL Workbe
 
 You can use the [testcaserepository.sql](https://github.com/seleniumbase/SeleniumBase/blob/master/seleniumbase/core/testcaserepository.sql) file to create the necessary tables for storing test data.
 
-If you were able to successfully install MySQL, you can now install the remaining MySQL requirements:
-```bash
-pip install -r requirements.txt
-```
-(NOTE: This install uses Selenium 2.53.6 rather than the usual Selenium 3+ from the standard requirements file due to compatibility issues with running browser tests on headless server machines.)
-
 #### Configure your MySQL DB for SeleniumBase
 
 You'll want to update your [settings.py](https://github.com/seleniumbase/SeleniumBase/blob/master/seleniumbase/config/settings.py) file with your MySQL DB credentials so that tests can write to the database when they run.

seleniumbase/fixtures/base_case.py

@@ -49,15 +49,10 @@ def test_anything(self):
                                         MoveTargetOutOfBoundsException,
                                         WebDriverException)
 from selenium.common import exceptions as selenium_exceptions
-try:
-    # Selenium 3 (ElementNotInteractableException does not exist in selenium 2)
-    ENI_Exception = selenium_exceptions.ElementNotInteractableException
-except Exception:
-    # Selenium 2 (Keep compatibility with seleneium 2.53.6 if still being used)
-    ENI_Exception = selenium_exceptions.ElementNotSelectableException
 from selenium.webdriver.common.by import By
 from selenium.webdriver.common.keys import Keys
 from selenium.webdriver.support.ui import Select
+ENI_Exception = selenium_exceptions.ElementNotInteractableException
 
 
 class BaseCase(unittest.TestCase):