Add _wait_till_text_present_in_element method

* add selenium configuration group
* add implicit/explicit wait and set page timeout

Partially implements blueprint: selenium-integration-testing

Change-Id: If39a5dcbac45635ad9988edfdc1830aeabc663a4
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Change-Id: Ie3f8301995d685bc1b31076aa99ec2d692ad3330
Merge "Add _wait_till_text_present_in_element method"