Migrated test architecture to Page Object Model Design

[smarshy]

This PR migrates entire selenium test pattern to follow page object model design. A new app has been created for the migration. It separates pages into objects, each linked to its relevant element locators. The tests have been refactored to interact with these page objects. There is a further reduction in duplication.

Earlier, the tests were very brittle. Small changes in UI (eg. page url, selector element) would lead to a need for several changes in the tests. One had to manually search and make changes for each relevant test within a file as well as across them. By migrating the entire pattern, any change in the ui needs to be followed up with a change at only one location, thereby making the tests more maintainable and less brittle.

Since there are plenty of changes, I am linking relevant blog here
Please review and suggest changes.

Fixes #376 , #369

cc @nidhimj22 @tapasweni-pathak

[coveralls]

Coverage increased (+5.02%) to 88.718% when pulling 925fd05 on smarshy:addPom into 09a6837 on systers:develop.

[tapaswenipathak]

This looks good to me.

@nidhimj22 Let me know when you are done, I will test and merge.