Add deprecation warnings for class name, tag name locator strategies.
Deprecations warnings will now be thrown for:
* 'tag name' in the native context
* 'class name' in the native context
* 'class name' in the web context
'class_name' is now a valid locator strategy for checkValidLocStrat
Add test for new class name locator
rename createCommand createGetElementCommand
Adding unit tests for new exception throwing
Add test for incorrect UIA class names