v0.3.1

Switch to selenium>3.
Add continue_on_error flag.
Implemented helper functions:

• connect_webdriver
• load_page
• wait_for_presence
• wait_for_visibility
• click_element
• send_keys
• hoover_over_element
• switch_to_iframe
• get_table_data
• get_element_text

Full Changelog: v0.2.5...v0.3.1