Add 'next' and 'prev' buttons
rename 'submit' to 'clickNext'
Fix page elements
Add create environment method
Refactoring test_cluster_network according new creation of environment, delete 'skip' attribute
Refactoring tests according new creation of environment
Rename method 'createEnvironment' to 'create_environment' and change  imports to relative
Merge pull request #28 from Mirantis/create_environment_dialog

Create environment dialog and tests refactoring according dialog