Integration tests - page objects pattern

First pages:
* pageobject - the base page for all page objects
* loginpage - the login page object
* basepage - base class for all dashboard page objects
* adminpage
* projectpage

First test:
test_login - a basic scenario test:
* checks that the login page is available
* logs in as a regular user
* checks that the user home page loads without error

https://wiki.openstack.org/wiki/Horizon/Testing/UI

Partially implements blueprint: selenium-integration-testing

Change-Id: Icad82f5f7810c348ddc30cd767f1d3bf5ecb926e
Merge "Integration tests - page objects pattern"